Hello Aspirant,
Yes of course, you can. If you have qualified NEET 2020 as per the qualifying cut-offs given below then you are eligible for stray vacancy round even if you have not appeared for any other round of counselling :-
For complete details about NEET 2020 cut-offs kindly check out the link given below :-
https://medicine.careers360.com/articles/neet-cut-off
Stray Vacancy round is conducted by the respective institutions itself, no any other organization is responsible for it and this round is conducted to fill the vacant seats which are left out in the NEET counselling and it is not compulsory that every institution must conduct stray vacancy round because if they have seat remain vacant then they can conduct stray vacancy round to fill up those seats.
I hope this information helps you.
Good Luck!!
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile