how to get BSES Old light bills of 1995?

For filing RTI the supplier even today must be BSES, and the bills have to be retained as per Retention period as stated in BSES records maintenance.  As per my knowledge, the retention period of such records is a maximum of 3 years only..  If some other private entity like TATA has taken over Distribution, then they are not under the ambit of RTI Act, being a private entity.

Just google, as I have seen several advertisements in which the Outsourcing agency is providing such bills as they have such such electronic copies of the record of BSES.