With 81 percentile in JEE Mains and SC category, your chances of getting a free seat (full tuition fee waiver) in an NIT depend on:

1. Home State vs. Other State Quota – You have a better chance in your home state NIT.

2. Cutoff Trends – SC category cutoffs vary by NIT and branch.

3. Tuition Fee Waiver (TFW) – Under government policies, SC/ST students in NITs usually get full tuition fee waivers, but you may still have to pay hostel and other charges.

To confirm your chances, check JoSAA cutoffs for SC category from last year for your preferred NIT and branch.