Hello aman,
You need to have more than 60% aggregate in your graduation if you are from general and 50% if you belong to SC/ST/PWD. Final year students can apply for the RBI B examination if they are above 21 years of age.
So unfortunately now you cannot appear for the examination, you have to wait for the next examination which will be held in next upcoming year.
I hope it helps,
Best of luck
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile