I can confirm that this is not true in the case of IITs. Admissions are purely through a your score in a common examination and nothing else.

Getting into CS/ECE in an IIT (especially the ones of repute) needs you to be in the top 0.01% (or top 1000 among a million) that give the exam every year.

It is almost a certainty that every student that ends up getting a top 1000 rank for IITs has slogged his ass off for the 2 years of their life simply to get in.