Hey!
If you have already registered for Round of All India Counselling, you needn't register again for Mop up round. Only those candidates who havent registered earlier need to register afresh. This is an online procedure. The mop up round is conducted by DGHS for Deemed and Central Universities. In the mop up round the net vacant seats due to non joining, non reporting from Round 2 will be published in the seat matrix and eligible candidates will be allotted seats according to choice and merit.
Who are not eligible:

Candidates who have joined in Round 2 of Deemed/Central Universities are not eligible.

Who are eligible:

Candidates who are registering for the first time
Candidates who have registered but havent been allotes seats in Round 1 or Round 2
All those Candidates who are holding a seat from Round 1 or Round 2