Yes, 98 percentile in JEE Main is a good score and can get you into NITs, but it depends on:

Category:

General: Chances in lower-ranked NITs or core branches.

OBC/SC/ST: Better chances in good NITs and better branches.

Home State Quota: Helps you get better options in your state’s NIT.

Branch Preference:

CSE/IT in top NITs: Tough at 98 percentile.

Core branches (Mechanical, Civil, etc.): Possible in many NITs.