Geology

This is possible. You can take admission here.

Download the course brochure from this link. It contains the breakup of seats:
https://manipal.edu/mit/programs/program-list/msc/msc-geology.html

Yes, you have a chance of getting the seat according to your rank and it is too good enough to get a seat in AU.

Yes, take the subject combination assuming that you are talking about class 12th, you can take these three subjects. If your school allows it and if not then probably can't talk to them and tell them that we will give exams in externally, if it is allowed in your school. But, it is not allowed in all the schools and if you question is related to college level then definitely in BA Programme you can take these three subjects combinations, but depends on your college or university.

Yes, I can definitely tell you the fee structure, but before that you need to tell us which college and university are you talking about.

Hi,
Sorry, but you are not available for spot round, because you have no rank so that's why try another college.

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.

Get the M.Sc Geology details here :
https://www.shiksha.com/science/course/m-sc-in-geology-presidency-university-kolkata-college-street-271070