IIIT

At IIITs, reserved category students (SC, ST, OBC-NCL, EWS, and PwD) can avail tuition fee concessions as per Government of India rules. SC/ST and PwD students are fully exempted from paying tuition fees, while OBC-NCL and EWS students may receive partial fee relaxation depending on the institute's policy. Other charges like hostel, mess, and exam fees are generally applicable to all categories. Students must provide valid caste or income certificates during admission to claim benefits. The exact concession amount varies by IIIT, so candidates should check the specific institute's fee structure before applying.

It is almost impossible that you can get CSE or ECE  branches any college but there are little chances to get environmental engineering, Biotechnology type branches in lower IIIT'S.

Personal suggest for you is to take drop.

If you belong to general category it seems impossible with this rank to get a seat in any IIIT.Still you can opt for private or deemed universities whose cut off is much lower than IIITs or if you belong to any reserved category you can apply in lower demanding programme in IIIT kancheepuram or IIIT una.

Yeah you can get ECE in NIT Mizoram and EEE in NIT Nagaland, and CSE in IIIT Manipur. The best option I can recommend here is ECE from NIT Mizoram.