M.Math is quite thorough in different ways, it is best not to end up opting for it without vital information. As a brief interpretation, you really do not require programming skills to further opt for the M.Math course. 

• A very intensive knowledge of linear algebra, real analysis, and basic abstract algebra is required prior to joining the M.Math course. Despite that, the course is very challenging. 
• The academic background does not necessarily affect the course you are about to take up. There are students who arrive from an engineering background. 
• It is best to go through the coursework of Mathematics and decide whether or not you are inclined towards it or not. 

M.Math students usually secure placements at a variety of companies, but achieving that howsoever is extremely difficult. Thus, choose only if you are confident. 

Well, whether the rooms are conditioned or not doesn’t matter as you are there to study and not relax. But, I can tell you that there is no such facility.

• But if you're coming to ISI or any other good Indian institute, like IIT, IISc, BITS, etc. for AC hostel rooms, please restrict yourself from doing so.
• No elite Indian institute provides AC rooms in UG. If you are so ardent about AC then you can get one at your own expense.

If you're searching for AC rooms, then you should opt for the college which gives you all kinds of things to cut your time and not a college that gives priority to academics, placements, research, etc.

If you want one there are multiple private colleges which provide you with AC rooms. There you can get all this and spend your time easily.

I am not fully aware of IITs courses but could still try to give some insight of the same on whatever I got to know from the internet. 

• The ISI M.Tech CS entrance exam includes an optional Objective Paper Mathematics and a Subjective Paper (you may choose CS).
• The majority of ISI's placements are in analytics firms so it would be advised to not choose ISI if you're looking for a core CS job.
• If you are interested in Algorithm Design, Machine Learning, and, most importantly, Cryptography, then ISI would be a good option. 
• After completing your MTech CS at ISI, you will have several research opportunities in ISI and also abroad.
• ISI has excellent theoretical CS faculty (Mathematics, Statistics, Cryptography, Machine Learning, Data Science). 
• So, if you're interested in learning more about these topics, you can come to ISI.

Please do not expect to find Developer, Coder, or Core CS work at ISI after completing your M.Tech. Students have a misconception about it and come here with high hopes which ultimately backfires.

My brother prepared for the Written Examination only in a week and scored close to 110 out of 150. 

Since my brother had a background in Semi-automated Trading, the interviewers were convinced about his love of Finance and Maths. He got waitlisted in 5 of the General Category lists and declined admission after the results.

If you are good at JEE Maths and have contributed to the field, it is important to show your passion to the interviewers. 

Kolkata is one of India's safest cities. This city attracts visitors from all over India and the world. That's why it's known as the "City of Joy." Bengalis are extremely friendly. 

ISI Kolkata is known to have the most sought-after institute in Statistical expertise. It has one of the best faculty members in India. Out of which, 30 professors were published in Standford University.

Moreover, you have got a seat in B.Stat which is considered one of the toughest examinations for Mathematics in Asia. You should base your judgement on the basis of a stereotype as letting go of this opportunity will be a wrong decision.

Almost 50% of the batch consists of Non-Bengalis here at ISI Kolkata. There is no need to worry as the institute also has a rigid anti-ragging policy.

While choosing between Kolkata or the Delhi campus students should apply to any one of them and not in both of them. Some commonly known facts regarding this are: -

• Both ISI Kolkata and ISI Delhi are very good for pursuing Masters in Economics.
• Both of the institutes have excellent faculty in their fields.
• Placements for both the institutes are really good, especially for PhDs.
• The interview list for ISI Delhi has been found to be bigger than that of ISI Kolkata

People believe that it is easier to get into ISI Kolkata when compared to ISI Delhi because of the location and fewer competitors for the institute which is absolutely wrong. Both the institutes have the same cutoff and entrance exam. The criteria for the selection of students is also the same in both the institutes therefore it is equally hard for the students to get into both.

According to a report published it has been observed that students find it easier to get into ISI Kolkata when compared to ISI Delhi. The cutoff criteria change every year and for last year it was: -

• For ISI Delhi the cutoff was said to be near 400 out of 600 according to the stats released in the official page.
• For ISI Kolkata the cutoff was said to be near 310 out of 600 from the same source.

Overall ISI Delhi is the better option here but ISI Kolkata is the safer one.

This course is relatively new and not many students have opted for it as of now. Cryptology Department at ISI is, nevertheless, extremely renowned in the academic circle and industry. A lot of students take their Ph.D. from here and the research is of remarkable quality.

To prepare, you may download the previous year’s question papers of M.Tech Computer Science. The idea is to know the type of questions asked, it'll be similar to the questions asked in the Cryptology paper. As for Math, focus on the MMA portion to understand TOMATO and solve all of it.

Perform well in the interview process or if you have good marks in the written exam that will help you too during the interview. If your scores are low, then get ready to face tougher questions and probably many. The interviewer will test your foundation skills. The trivial will take precedence. 

Even if your answer is incorrect just be confident and say it out clearly, they will help you with the final answer themselves. 

My friend is currently studying at ISI Kolkata, and according to him, there’s no specific course on Data Science currently. However, students belonging to M.Tech CS often get placed in companies for data science profiles. Thus, you must check the placement insights for M.Tech CS instead.

Here are some crucial placement stats for M.Tech CS batch in recent years. 

• The highest package offered was nearly 39 LPA
• The lowest package offered was about 13 LPA
• The Average package remained 18.8 LPA and the median package was almost 18 LPA
• Various roles offered mainly consisted of Analyst, Data Scientist, Business Analyst, Data Analyst, Quantitative Researcher, Trader, Resident Researcher, Software Engineer, etc.
• The major companies where CS students got placed included Microsoft, LinkedIn, Flipkart, Myntra, Zendrive, Yodlee, Optum, Sapient Razorfish, Fidelit, Oyo, etc. 
• Other companies that offered jobs for CS students included Alphonso TV, Goldman Sachs, JPMC, Trexquant, STAR, Reliance, Fourkites, Samsung, TeraData, Play games, ElasticRun, Blackrock, and more with annual packages ranging from 12 LPA to 35 LPA.

The placement scenario at ISI Kolkata remains absolutely impressive for almost all courses. Almost everyone gets placed, except those who are going for higher studies instead. If you are confused about the placement system at ISI Kolkata, you don’t need to worry at all. You can grab pretty attractive packages with your caliber.

There are two examinations through which you can take admission at ISI Kolkata for M.Tech CSE.

• GATE (CS) with a score greater than 720.
• Written test conducted by ISI Kolkata.

The written test conducted is of two types, i.e. Objective type questions will have mathematics paper (11th, 12th, and engineering level mathematics) and Subjective paper will have questions from Mathematics and one domain of choice.

One of my friends got admission to ISI Kolkata a few years back. Here are the reference books that she used for her preparation.

• Tomato - A book for B-stat and B-math by ISI
• Previous papers provided by ISI
• Solve the sample questions of JRF Computer science for more practice.
• Books from Ctanujit classes ( It contains a lot of mock papers)

You don’t need to solve the book completely but make sure that you know which kind of questions are asked by referring to the previous papers and then solve them accordingly.

For the technical section, the questions are very basic and test the fundamental knowledge in the chosen domain. You will see the pattern and important topics from the previous year and prepare for it.

It is important to score as high as you can in the written test as it has a higher weightage.

In interviews, you will face a panel of 12-14 professors from every domain. They often ask questions based on your background and ask to prove the theorems from the technical domain. The interviews differ for each candidate. If your written test goes well, you will see your name on the final list.