See if you have entered the wrong roll number then there are two possibilities. One is that the marks will be assigned to some other student and which will lead to cancellation and the second one is that there is no roll number assigned to what you have filled and your examination will get cancelled. This are the maximum possibilities. But if there are manual supervision and if NTA officials have instruction to deal with such discrepancies not to cancel, then only you can have some possibilities to get the credit. But for that you need to wait till the results are released.

I hope this answer helps. All the very best for your future endeavors!