Hi Sulagna!

Accepting a seat in NIT would bring you down from furthermore applying for NITs in the following year, but you are free to do up with IITs. Similarly If you accept a seat in IIT a given year you wouldn't be able to apply for the next year

Conclusively, You could take part in JoSAA and furthermore move onto NITs next year too, provided you don't accept any of the seat, which means you shouldn't be reporting to the RC

Do have a good read of the prospectus provided in JoSAA webpage before making in any proceedings

Good Luck for your future!

Regards