Indian institute of technology has no reservation for sports quota. 
The only people who get reservation are Scheduled casts and schedule tribes and Other backward classes. For iit, first you have to qualify Jee mains according to cut off marks ( according to your cast) after Jee mains, you have to qualify Jee advanced.

But NIT

There is 5% reserved quota for NIT, you need to have an adequate and a good score in Jee mains to avail that opportunity. In addition to the points secured from sports quota. It's for both national and state level. Also there are certain points which have been alloted to particular games.