Hi, once the time window allotted to candidates for admission, eligible through a particular list is closed then you will have to wait for students eligible for admission in the next list to complete their registration procedures. If by that time the university still has seats available for the course you wish to take admission in, only then the university will consider your registration and grant you admission.

 For example if you are eligible to book your seat through first list itself but you don't complete your registration process and document verification. Then you wish to book your seat by the next list, then you will have to wait for the students who are eligible to apply through that list and then if seats are still available, the university will grant you admission.

I would advice you to complete your registration process in DU and then if you wish you can withdraw you admission later. while doing so, do confirm about the last date to withdraw your admission and refund process from the university admission help desk, because after a certain set date the university might not refund the entire fee that you paid for the course.

Good Luck