You can list all the possible colleges which you might be interested in and then based on your constraints you cam eliminate them to get the desired colleges, you should consider the following criterion in deciding the college. Quality of education, Fees, ,location, job opportunities .

Here you can get the list of some of the best colleges for MSc Mathematics in India

https://university.careers360.com/colleges/list-of-msc-in-mathematics-universities-in-india