sajeev,
It is a basic "attitude" problem. Most officers will feel that a
RTI Application is either to "expose corruption" or to "expose lethargic working".
I am surprised that you had to go through such a effort to file a
RTI Application. Probably reflects the general attitude by Government Servants in Kolkata. There have been many complaints, not only about Public Authorities in West Bengal, but also about the working of the State Information Commission.
Based on your further clarifications, if you have someone staying at the place in Kerala (the address where your PP form has been sent) you can file a
RTI Application to the Assistant Commissioner of Police under which the Police Station falls. OR, you can wait for 30 days to get the RPO Kolkata reply and then file a
RTI Application.