Some of my friends studied at MNNIT, so I might be able to answer your question. It is suggested that you choose Mechanical at MNNIT Allahabad rather than Civil at NIT Trichy.

Your branch of choice is more important than your college preference. In terms of opportunities, Mechanical Engineering has a slight advantage over Civil Engineering

Mechanical at MNNIT Allahabad has a consistent placement record. Mechanical students receive more job offers than Civil Engineering graduates. PSUs often choose Mechanical Engineering graduates.

Finally, everything depends on your interest and choice. So think wisely and then make any decision, because this will be the building blocks of your career.

Both IGDTUW Delhi and PEC Chandigarh are reputed colleges and are equally good but both these courses are very different from each other. 

If you are interested in higher studies and want to do M.Tech or Ph.D., then only opt for PEC civil. The pressure for studies would be less. You also have no restrictions in doing extracurricular activities. Here you can focus on other things besides studies, like on your hobbies or learning and developing a new skill or a new language which can be helpful in your career. 

Here’s a brief overview of the courses mentioned in the question. 

Hope this answer clears some of your doubts.

The term attractive is relative, in the context of a CV or resume. You just showcase your skill-set, education, work experience, etc in these documents. Yes, a CV can be well-organized or well-formed. A well-formed CV may be found attractive to one recruiter and in the very same way, it may be found dull to some. So, there is a pinch of luck factor also required. So first you need to consider for what company you are going to apply. Your CV should be target-specific and must target a company that is interested in the skills you have. For Example, If it is an analytics firm then put some extra effort to showcase your interpersonal skills as well as your extracurricular activities. If it is a core technical job then vocational training and other academic projects should be highlighted well.

To make a good cv consider the following points. 

• The font size should never exceed 16. A minimum would preferably be 12. This font looks professional.
• Use professionally used fonts like times new roman etc. Don't forget to make certain comments bold or underlined.
• You should have an email id that doesn't contain anything funny. For ex- if someone named Aditya Ghose makes his email id adityarocks@gmail.com it will not come across as professional.
• Don't forget to use margins in ur CV. Your CV should look clean and spacious.
• The declaration is not needed for campus placement. If you try off-campus then you have to write a declaration to verify that it's your cv.
• Make use of a table to write down your academic qualifications and your percentage of marks, CGPA, etc.
• The most important thing to note is that a CV should never start with the title CV or Resume.
• Don't forget to convert it to .pdf format as it looks more professional.

Hope this was helpful. You can also consult various websites to understand the process better. You can also download some formats for your reference.