Hey Shriya!

Following is the eligibility criteria for Mop up round counselling :

1.       Candidates who clear the NEET UG Cut Off 2019  can only appear for NEET Mop Up Round.

2.       Candidates who have not registered for NEET UG Counselling 2019  before, can participate in the Mop Up Round.

3.       Candidates who have registered in NEET Counselling 2019 but did not get a seat can appear for Mop Up Round Counselling.

4.       Candidates who participated in the 1st or 2nd round of NEET UG Counselling 2018 and got a seat cannot participate in the Mop Up Round.

So , it is clear from point 2 that if you have not participated in second round of counselling , then you can register for mop up round of counselling 

Hope it helps!