Hello,

It is a quite a big mistake , as it is your 12th roll number. But i don't think that it should cause much problem. As you have qualified one of the toughest exams. So it shoudn' cause any problem.

I also entered wrong school name in application form. But i didn't face any problem in councelling. Yet you can talk to the helpline number given and tell them a problem. They will tell you if there is a way. And you also prepare yourself. You can write a letter that i mistakenly entered wrong roll number. And requesting them to correct the roll number , if they raise any question on it. 

It will be better if you talk to the customer care ..

Thank you.