Depends on the authority u are dealing with.In some states while dealing with PA s under the state, applicant needs to pay postal charges.If its central PA applicant doesnt need to pay the postal charges. Please check rules. RULES are available here: RTI Guide
For detailed information on how to draft & file an RTI application, please see the "All About Right To Information" links on the homepage & RTI Guide section of the portal.
If you have any further doubts, please post them here and our members will be pleased to guide you further.