A self attested copy is nothing but you signing on the xerox copy of the original results. But if you have submitted the original marks sheet and original admit card, it is not at all a problem. At any given time, an original document is the one. So there is nothing to be worried about in this. The application will neither be disqualified nor rejected for this reason. So do not be worried about this at all. We know it might be scary but this is not a reason why an application will be rejected.