hi,

YOU can apply for both IITS and NITS accepting your score.

You will surely get admission in IIT but not in the top discipline of your choice

Basically this depends upon ranking and cutoff for the session instead of marks, higher the difficulty level of paper-lesser the marks required to make good ranking

here is the link below to check out more details of which IIT or NIT ACCEPTING various scores

https://www.geeksforgeeks.org/gate-marks-needed-to-get-into-iits-nits-etc/

ALL THE BEST.