Hello Pratham,

Hope you are doing well.

As per your query, for admission in MSc Physics in IITs , you have to give IIT JAM Exam whose eligibility criteria for that particular course is as such:

• Essential subjects in Bachelor's Degree along with the minimum duration:

Physics for at least two years/four semesters and Mathematics for at least one year/two semesters.

• Essential subject in 10+2 level:

No Restrictions

Therefore you cannot take admission in IITs for MSc Physics course if you have done your undergraduation in BSc Geology.

For further information related to eligibility criteria for different courses in IITs, please visit the link provided below:

https://university.careers360.com/articles/jam-eligibility-criteria

Hope this helps you. All the bes