is it ok if i dont register for nptel exam (its not related to any of my courses)

so im in 2nd year, and we got mail for registration, and i keep getting mail to pay 1k, so do i have to do it, or is it cool if i dont take this bullshit nptel thing, i have no idea cuz i have no info about it in class, was just mailed about it. pls lemme know