Dear aspirant

The eligibility is the same as JEE MAINS, there is no other eligibility criteria for only IIIT(s); but again it depends on institute to institute.

If you want to know eligibility esp. for particular institute go to their website and check (like for IIIT Hyderabad).Apart from it genereally for Govt. funded IIIT (which follow JEE MAINS eligibility ) are:

• 1.You must have passes 10+2 with science stream.(obviously)
• 2. Score of atleast 75% in 12th or being in top 20 percentile.

But to get into any IIIT you have to score decent marks (or rank) in JEE MAINS.