Hello Vinod,

Unfortunately since you are a BA student and the institute you are talking about is IIT, as you have already seen the eligibility is Geology for three years/six semesters and any two subjects amongst Mathematics, Physics, Chemistry and Biological Science. Hence I am afraid there is no other way to join the course ,you may have to do BSc degree in Geology.Most of the other universities like Jadavpur University, Andhra University, Anna University etc have mentioned eligibility criteria as BSc in Geology or equivalent.Hence you may have to check with the respective department whether BA in Geography is accepted for the MSc programme. However there is one option for you which is integrated MSc Geology in IIT. Its a 5 year course though.

Hope it helps.