Hii!
The eligibility criteria for GAT - B 2021 for biotechnology states that the candidate must have passed or have a degree in AH or equivalent from a recognised university with minimum 60% marks.
So, if you satisfy this criteria, you can apply for the exam.
The link given below will help you with more information-

https://www.google.com/amp/s/university.careers360.com/articles/graduate-aptitude-test-biotechnology/amp

Hope this helps.
Good luck!