To rectify the mistake you have committed while filling the form, check whether if the site is still open for editing the application forms. If yes, you can go and edit the name. Another option is if the last date for application is not yet over, you can try applying again with different mail id. This option worked when I made a mistake in higher secondary mark when applying for a bank exam and it worked. I am not sure how ii works in your case, you can try though. Else you don't have any option, you have to go ahead with the same application form and during interview, try explaining the mistake politely. All the Best!