Hi,
Master's in Physics is a really good course which has a ton of good opportunit in the future. Specially if you get placed in the campus itself with good GPA you will really thrive. Speaking of jobs, you can get into construction, research institutions, agriculture services and educational institutions. Specific jobs mainly which you can or will get are
1. Research scientist
2. Teacher
3. Technician
4. Radiation oncologist
5. Physics professor
Yes ISRO does offer jobs through their recruitment boards. You will just have to keep visiting their official website and keep Checking their vacancies. They will conduct an exam and based on your results you will easily get into ISRO.
Good luck