@tolip
You can only renew the RTR license from the WPC RLO that issued it to you .
For eg if you passed the exam in Delhi then you have to get it renewed from Delhi itself
If you passed from Chennai then yes you should visit Chennai RLO to renew the license
Depending on the RLO they might ask for additional documentation like I mentioned above
You will need a certificate of experience from the flying school last flown
You should be able to renew it on the basis of 30 hours of lifetime provided you get the documentation right