Hi Shiyam,

There is no any compulsion to conduct a COVID-19 test before appearing for exam because NTA has issued the guidelines but yes if you have been tested positive than you are and you are currently infected then you will not be allowed to appear for the exam. The admit card is sufficient.

Please note that you are required to fill a self declaration form in the front of invigilator. As that form signifies that you have no any symptoms of COVID-19 and you are strictly following all the guidelines issued by the Government in the public heath interest.

Refer here for more info - https://news.careers360.com/neet-2020-admit-card-covid-19-instructions-keep-in-mind

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!