JEE Mains has a  correction window. So you do have a chance of rectifying the mistakes that might have occurred during the filling of the application form. But if the corrections date has been past and you haven't made the corrections to the application form, NTA will regard the application form as final and will not make any changes on its own. The correction window is the last chance for corrections to your application. Depending on the error that has been committed, it might affect your admission as well.