Yes definitely! Mathematics and the engineering fields like Biotechnology in general are very much interlinked and you can pursue one after or before completing a graduation in  the other subject. So, essentially yes, you can do a graduation in maths after completing your graduation in biotechnology.

You can also use our college predictor to see your chances in all the colleges:
https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

Hope I have answered your question. All the best!