Dear Savita

Mop up round is different from open round counselling. There is no mop up round but open round counselling is done in AIIMS. When seats remain vacant, AIIMS calls all candidates who have qualified in the exam, this is known as open round counselling. It is usually held after the 3rd round of counselling. In 2018, it was held for 103 vacant seats(except Delhi) according to notice vacant seat position dated 20.08.2018.

Hope this helps you.