Is it better to take CSE at NIT Surathkal or mechanical engineering at IIT-KGP?

The answer to this question depends mainly on your interest. Mechanical and CSE are diverse branches with diverse scopes. You need to analyze your own inclination only then can you make a sound decision. If you aren’t sure if the branch you can decide based on your future goals.

• If you want to land a job right after graduation that too a decent package, choose CSE over Mechanical because that branch has more job opportunities. 
• If you are planning to pursue higher studies, especially in Physics-related courses, choose Mechanical. The branch is very intriguing and opens many doors to higher studies. 
• If you value colleges over branches then choose IIT KGP as it’s way ahead of NIT Surathkal. 

Lastly, I will advise you to opt for Mechanical only in first and second-generation IITs. So you can opt for NIT Surathkal or Trichy over third-generation IITs but not over first and second-generation IITs. Hope this clears my point.