Finding surevy number

The records published for 2001 (ready reckoner) for Pune, does not contain survey number for a property that was purchased in 1993 and sold in late 2019. It has been subsequently included in the later years. However, for the purpose of finding fair market value, the evidence of the then circle rates is needed so that the LTCG calculation and Bond investment amount is passed by IT authorities. How is the base rate ascertained in such cases? can an expert in taxation and/or property law advise on this? Thanks.