Hi,
The penis size you have mentioned is already more than average size of indian male penis. There is no evidence based treatment indication to prolong the penis of your length. Anyway if you try desperately, you will get multiple luring ?therapists who will claim to enlarge your penis. So, remember if you are able to satisfy your partner, there should be no need to increase the length of the penis. I assure you, it won't give you extra edge in sexual performance!
Next Steps
introspect and decide the future course