The Sub-Registrar need not go into through enquiry of title. If he satisifies with the document filed in support of title, he can register the document which is presented first. If the other party aggrives with the registration, he has has to approach the Court for cancellation of registered document.
If it is pointed out to him he will not proceed. It would be required from the presenting parties to show their bonafides, naturally both would not be genuine parties. At the time of registration the seller's credentials are checked.