Rather than giving you a direct answer, I am going to evaluate all The aforementioned institutes individually on the basis of some common parameters like placements, brand name, campus life, opportunities, and alumni.

IIT BHU ECE

• Core placements are rare and students mostly build their profile for software development companies by becoming proficient in various programming languages, doing competitive coding, doing projects, and trying to build a computer science-inclined profile. A handful of students target core engineering roles.
• The brand value is similar to other colleges mentioned
• The campus is rather old and might disappoint freshers expecting a good college life.

IIT Guwahati ECE

• Unfortunately, I have no knowledge about this Institute. However, I recommend you contact the seniors of IIT Guwahati for the same.

IIT Hyderabad Maths and Computing

• Usually, MNCs attract top-tier software and financial services firms. If you are a hardworking student, it wouldn’t be difficult to secure amazing offers at top firms.

IIIT Hyderabad CSE

• IIIT H has possibly one of the best computer science departments in the country. 
• You have to do core computer science courses right from the first year.
• Many students get selected for Google Summer of Code and IIIT Hyderabad has its alumni in top-notch firms. 
• Being highly academically oriented, IIIT Hyderabad has minimal campus life and extracurricular activities.

Ultimately, it’s a matter of preferences and what you are looking for in your degree.

It depends mainly on your core interest in the study. The field of Computer Science is vast and out of the blue, which ensures you multiple opportunities compared to mathematics and Computing. If you are interested in coding culture, then it is better to choose BHU for CSE. 

The points given below will give more clarification about BHU.

Campus – IIT BHU is situated in the middle of the city, so you will have easy access to coaching centers and other places. The infrastructure is pretty good and old, and the students are given a resourceful atmosphere for their studies.

Alumni – You have a strong alumni network in the CSE department.

Placement support - The recruiters from big companies, including HUL, RIL, KBR, Amazon, and so on. You will get the opportunity to sit with these companies and will be placed in high-salary jobs based on your talent in the CSE field. You also get the chance to impress with your GATE score here.

IIT BHU Placement

Both IIT Indore and IIT BHU are well-reputed institutes. But IIT BHU is ahead of IIT Indore in the aforesaid points. So, you should choose IIT BHU for a better future.