Science

The candidate should have a Bachelor's degree in Agriculture or Horticulture or Forestry from a recognised university in India. The candidate must also have passed the degree with minimum 50% marks. Some colleges do allow the admission with any basic graduation.

No, you can't opt for forensic science course as you need to have Bachelor’s degree in science or equivalent qualification.

You could try Indian Institute of Astrophysics, Bengaluru. It is one of the oldest institutions in India (1786 AD) and right now, the premier institute for Astrophysics (in my opinion). They offer three courses:
M.Tech, Ph.D. Dual degree GATE written test)
M.Sc, Ph.D. Dual degree JEST written test)
PhD

After your B.Sc Microbiology, you can go for M.Sc. (Microbiology). You'll be acquiring knowledge at a higher level than what you studied during your Bachelor's degree, and the course should help you develop the necessary skills for your field of work. With a postgraduate qualification on your CV, se

Follow the link below for syllabus for BHU PET
https://www.shiksha.com/university/bhu-banaras-hindu-university/bhu-pet-exam-syllabus.

Hi,
The exam date is between April 28 -29, 2019. Applications are already going on and admit card will be issued on April 13, 2019.

Fill in the admission form to get started with and then follow to instructions.

Well, you have to go through the link below and you can also check the admission process and the respective dates of the exam individually:
https://www.shiksha.com/science/colleges/m-sc-geology-colleges-india.

The eligibility differs from college to college. You can apply if you passed a Bachelor's degree from recognised board.