Hello

The salary depends on what the person will be doing after completing masters degree. If one opts to be a teacher after MSc Physics then he will earn more than the one doing MSc in Astronomy. The best you can do in the field of astronomy i sto become and astronomer and for that you will need a PhD (bare minimum).

After Msc in both the subjects you canapply for different government jobs (the salary only depends on the rank you get inthose examinations and not your subject during masters).

But, you will have a wider scope if you choose MSc Physics as after completing the course you will be eligible to teach in schools, colleges (after qualifying NET), become a researcher, lab technician etc. The salary as I said, will depend onthe job you get.

A teacher (government schools) can initially make up around 5lpa while a lecturer can make around 7.2lpa and more.