Hello dear..
IIT and in some cases they are better than the IIT.Just ask someone from NIT how good packages they are offered. And just think when a company comes for placement in IIT and see your preparatory course certificate. Just think that” is that impressive?” You have also wasted 1 year of time from your college.
And the most horrible part- IIT will take an exam after the one year and if you pass in that exam only then you will get admission in IIT and if you dont then you have to see the door. And the exams that they take are not as semester exam. that exam is tough as jee advanced exam so you have to think about it. If you dont pass you just wasted one more year and you have to take admission in some other college like LPU as you have not apllied for any other exam.
But if you take admission in NIT it will be a super safe zone.
No doubt suratkal is better.
World is not easy my friend.
Best of luck