Hii!
Whether it is a government college/ university or a private college/ university, most of them provide admission into biotechnology course via entrance exam only, and rarely on merit basis.
Various universities across India conduct their own entrance exams for BSC biotech or MSC integrated biotechnology courses and select candidates as per their performance in the entrance exam.
So, you need to apply and fill the registration form for the college you are interested in, sit for the entrance exam, clear it with good marks to get a seat in the college you desire.
Hope this helps.
Good luck!