The top college for pursuing bsc microbiology in Delhi is Gargi College. Amity University is another good one. BHASKARACHARYA college is also a decent one. The other available colleges are -

1. Institute of Applied Medical Science and Research
2. Bhagvati College of Science
3. Delhi university
4. SGT University
5. Sharda University
6. Galgotia University

Refer to the links below..

https://www.careers360.com/colleges/gargi-college-delhi/bsc-microbiology-hons-course

https://www.careers360.com/colleges/bhaskaracharya-college-of-applied-sciences-new-delhi/bsc-microbiology-hons-course

Best wishes.. Thank you.