Hello!

To apply for a UG course (BSc Biotechnology), most universities admit you on the basis of your 10+2 marks. There may be some institutes that require a separate exam for admission. For Btech in Biotechnology, you have to give your state's CET or JEE (with pcm). In certain institutes (VIT, SRM etc) you can get admission for this course even if you don't have maths in +2. Their entrance requires pcb. 

Almost all colleges require clearing entrance exams for admission in PG (MSc/MTech).