.dear bhavesh,

Actually Bhavesh i am not 100% confirmed about it Butng after a lof of googling i came a conclusion that  you are eligible for IIT JEE.

If you get a seat in IIT and if you don't with draw then you are not eligible for JEE advanced .But there is no mention of such rules for nits so you can give jee mains and advanced again 

Hope you got your answer .

Good luck :)