Hey, To be eligible for Bsc Physics a Candidates should have passed 10+2 Examination from any recognized Board in Science with Chemistry, Mathematics, Physics and securing at least 75% marks in average obtained in Chemistry, Mathematics & Physics are eligible. 

So chances are that you may be eligible if your Maths mark is more than 75%. It will be wise to call the institute and inquire about this matter. Because they have not mentioned anywhere if it is compulsory for the subjects to be main. I hope this helped.

best wishes