Hello Bisheshwar,

With the rank you specified, you can easily get admission in NIT allahabad. You can get all other branches except CSE (Computer Science and Engineering) and IT. In IIIT delhi you have more chances to get branch as per your wish as you are from delhi. Here also you may not get CSE but you can expect other branches like Computer Science and applied Mathematics. You can easily get other branches. For CSE after round 6 closing rank in 2018 was 6350, which is close to what you got.

Good Luck !!!