Dear, most often the post card size picture is necessary to appear in the NEET exam, if you can arrange it then there would be no further issues. But since it's a pandemic time you may not be able to arrange it, take passport size photographs with you, but I don't know whether they will allow you to sit for the exam or not. You try to arrange the post card size photo, it's essential very often.

Good luck for your exams!!!!!