I would just like to provide information as to how such a case in handled in USA. First of all, the PA has no obligation to provide any answer to any questions, only copies of existing records. If the records are huge and some of the records are not to be disclosed under FOIA (similar to
RTI in India), then PA has to make an index of the records and give an explanation as to which parts are not to be disclosed, and for what reason.
The newspapers have requested copies of huge records consisting of over 2.5 lakh pages. The PA had to make an index and supply the index to the requesters. Then requester had the option to ask for specific records, and challenge the ones that PA refused to disclose.