Hello Ayush,

Yes there are quite high chances of you getting into a good branch in IIIT or  in NIT but cut off for any college depends on the number of seats available, difficulty level of the entrance exam and the performance of other applicants in the exam so they can change too. Since you haven't mentioned which branch of Engineering you are interested in and the state to which you belong, here is the careers360 link for you to refer to know more about  the closing rank of different branches.

https://www.google.com/amp/s/engineering.careers360.com/articles/nits-cutoff-for-top-btech-branches/amp

Hope this information was helpful.

Good luck!