I got 121k(obc 35k) rank in jee may i get NITor IIIT.

Hey

Getting NIT or IIIT would be very difficult with this score. Only chance for getting NIT with this score is if you have home state quota as well. Still if you wanna check for previous year cutoffs of NIT's you can check on the following link
https://www.google.com/amp/s/engineering.careers360.com/articles/nits-cutoff-for-top-btech-branches

Here the cutoffs are categorised branch wise so it would be more convenient for you to check.

Hope this solves your query.
Good Luck!