I suppose you are from a public authority. There is no time limit as far as records are concerned. Records of any period can be sought. Records exempted under Sec-8 & 9 are also to be disclosed after 20 years. You must frame a Record Retention Schedule (RRC for short), if already not available. In GoI, such a schedule exists. Based on this RRC, you may distroy all such records which are outlived its normal retention period as per RRC, of course excluding those involved in Court Cases, Deptl Proceedings or Arbitrations etc. Procedure for weeding out old records should be followed and details of records distroyed should be maintained.
If the information sought disproportionately divert the resources of your Public Authoirty or would be detimental to the safety of preservation of the record in question, you can ask the applicant to inspect the records and identify specific information, copy of which can be supplied to applicant. (Ref Sec-7).
Please remember that under Sec-4, it is obligatory on the part of the Public Authority to maintain all its records duly catalogued and indexed and disseminate information to the public.