Dear aspirant,

After doing Msc. everytging depends upon your knowledge. If you dont have complete knowledge then clear all your basic and learn each and everything by giving at least 2 years since physics is a very strong and wo derful subject.

After the complete knowledge of physics you can prefer the competative examination which ISRO used to organize periodically every year.

After the exams you need to give interview which will test your complete knowledge of physics which will be based on Numericals portion.

Hopefully this will help you.
Thank you.