B.Sc Geology

Not three, but Physics, Chemistry, Mathematics, and Earth Science are the four main subjects covered under the BSc Geology course curriculum. The combination of these subjects offers an in-depth understanding of Earth's process, structure, and Science. 

Here is the list of colleges for doing B.Sc Geology. You also get information about admission procedure
https://www.shiksha.com/science/colleges/b-sc-geology-colleges-india
Hope it helps you well.

Hi,
Both are good, I think you should prefer B.Sc Agriculture. As it is a demanding field, and there is requirement in IARI. You will get good opportunities. All the best.

Yes, for this college, admissions will open from June. You can apply online that time.
Good luck.

Yes, you can look up to universities like:
Dr. BR Ambedkar Open University
IGNOU.

Yes, there is a good chance to get admission in this college.
I hope you will get this college.
Good luck!

Below are the best institutes for B.Sc Geology with their cities mentioned:
Dibrugarh University Dibrugarh, Assam
M. G. Science Institute Ahmedabad, Gujarat
Assabah Science and Arts College Malappuram, Kerala
M.E. S Ponnani College Ponnani, Kerala
Himalayan University Arunachal Pradesh
Presidency Institute Kolkata
Sree Narayana College Cherthala, Kerala
Shivaji University Kolhapur
Hope this helps you.