MSc Data science gives you a better job perspective than MSc Physics. Although, MSc physics have jobs like scientist in BARC, DRDO, Research Assistants, teachers in Institutes like Aakash, Allen etc(if done MSc from IIT's preferably) then you have a good chance. But if not and you want to do job then if you want to be safe then go for Data science. If you are affectionate about physics then only go for it as your interest for physics will return back all the affection you have put in it.

If you want to differentiate in respect of salary package wise then you should opt for data science because on an average a data scientist's starting package is around 6-8 lakhs per annum in India. Whereas the staring salary for a Physics PG candidate is  6-7akhs per annum in coaching sectors and if you go for BARC then the package is around 10LPA for BARC,MUMBAI. So now you are able to self analyze and can choose by yourself.

I hope my answer helps. All the very best for your future endeavors!