Can we change our base location ?

are you currently reporting to Patna office? I also asked the same from my supervisor but they denied. It depends on supervisor and manager. If there is no ODC for your project then they might transfer you. If you have valid reason then connect with HR once

Changing base location is tough. Pune to Patna? Unlikely without a dedicated ODC. Talk to your PM and HR, but don't hold your breath.