Hi there comparing the both Amrita Coimbatore and top IIIT insitute will result in draw or IIIT will get win. I'm saying so on behalf of some aspects such as fees, placements, college environment and many more.

Since top IIIT such as IIIT, Bangalore is a Government institute so it sure do will possess more facilities as compare to Amrita Coimbatore. As well as the placement criteria is also good in IIIT as compare to Amrita Coimbatore. Otherwise rest depends on you.

You can go through College Comparison once with Careers 360 College Comparison tool(link mentioned below);

https://www.careers360.com/compare-colleges

Good Luck.