Hello there,
For doing any B.Tech course, you need to have maths as your compulsory subject. For Biotechnology, you need maths as well.

Here is a list of colleges offering BTech in Biotechnology in Tamil Nadu:
1. SNS College of Technology, Coimbatore
2. Kalaignar Karunanidhi Institute of Technology, Coimbatore
3. Jeppiaar College of Engineering, Chennai
4. Saveetha School of Engineering, Chennai
5. St Peter's College of Engineering and Technology, Chennai
For more information about colleges, you can visit the link given below:
https://engineering.careers360.com/colleges/list-of-engineering-colleges-in-india?state=Tamil%20Nadu&degree=B.E%20/B.Tech&branch=Biotechnology,Biotechnology%20Engineering

Hope this information helps you.
Good luck!!