Dear aspirant,

For B.tech you have to give entrance or you will be given admission on the basis of your 12th marks in which maths will be compulsory. In short maths is compulsory for taking admission in btech.

The colleges in tamil nadu which offers biotechnology are:-

1-SASTRA University Thanjavur - Shanmugha Arts Science Technology Research and Academy

2-St Peter's University, Chennai

3-Prathyusha Engineering College, Tiruvallur

4-Udaya School of Engineering, Kanyakumari

5-Vinayaka Mission's Kirupananda Variyar Engineering College, Salem

For more information you can check out the link given below-

https://engineering.careers360.com/colleges/list-of-be-btech-in-bio-engineering-colleges-in-tamil-nadu