Hiii

BLAT is conducted by Banaras Hindu University for admission to their five-year integrated law programmes in the Law Faculty of BHU. For applying in the BLAT exam one must have qualified class 12th exam with 50% marks and must not be of age more than 20 years.
So you are eligible for applying considered that you fulfil all the criteria set by BHU.
Refer to the link below for more details.
https://law.careers360.com/articles/blat

Thanks!!