Dear Akanksha,

AIIMS has a 2 step registration process. After completion of the basic registration you have to generate a code and do payments for the code generated.

Each candidate is allowed to pay for only one code. After payment you will be able to submit.

For UG courses please go to this official AIIMS website only -

http://ugcourses.aiimsexams.org/ 

and follow through all mentioned instructions.

All the best Akanksha!