If you are talking about the CBSE class 10th exams and you have already appeared for the exams and are willing to re-appear . The reason mentioned by you is not clear and so I am supposing that this is because , you have got less/unexpected marks in your exams. To be honest, it's really difficult for you to rewrite the paper in this pandemic situation where every school and college is closed yet.
I would ask you to check out once our country deals effectively with the virus and the vaccine is out, then only something can be said with surety, until then it's just the assumptions.
Hope that helps
All the best.