Hello

there is no way you can undo this right now, you should have changed that before, now you can only get admissio under OBC-Non creamy layer only.

You might contact them by contacting them at the information given at this page and request them: http://du.ac.in/du/index.php?page=contact-us but that seems difficult since everything is done online and the form editing of the forum is over now.

Hope this helps.