Hii

The final registration can be done on the official website.
Here i am providing the link for the same - http://mbbs.aiimsexams.org/
In the applicant login zone, enter the details and proceed to final registration.
Make sure before proceeding, you have generated RUC from the basic registration form.
In case you wish to login to basic registration form then use the following link - http://ugcourses.aiimsexams.org/

Hope this helps
Thanks!