Hi Vivek, if you go according to the JEE score then you have to wait for the cut off, otherwise there are various colleges that give admission on the basis of entrance.

No. It's very low chance for YOU to get an seat in NITs IIITs . And ofurse CSE branch usually demands best student, so it's very hard.

You can only get admission in NIT in 77 percentile score if you are SC/ST.but still you won't be able to get good NIT and ofcurse very less chance for CSE branch.

you cannot get goverment colleges but ofcourse there are many affordable private colleges in which you can try. And as per my knowledge,you can expect some scholarship too in colleges like amity,lpu,srm etc.