See if you have given the BSEB board class 12th examination in all the subject and you use it as a reference of graduating from high school, then you are eligible for the JEE Advanced 2021 as the eligibility for the JEE ADVANCED is that one can apply only two times one is on the year of 10+2 and another attempt can be done 1 year post 10+2.

To know more about JEE ADVANCED visit the link below:

https://engineering.careers360.com/exams/jee-advanced

I hope this answer helps. All the very best for your future endeavors!