A public authority is obliged to provide information which is more than 20 years old subject only to the provisions of clauses (a), (c) and (i) of Section 8(1) of the RTI Act. This means that in respect of the information which is more than 20 years old, the public authority may decline to furnish the information only if it is covered by Section 8(1)(a), Section 8(1)(c) and Section 8(1)(i). But in all other cases, even though the information may fall within the ambit of other clauses of Section 8(1), the disclosure by the Public Authority is required.
The RTI Act has no provisions about maintaining records for 20 years. The record maintenance has to be as per the practice of the public authority.