Mismatch between Possestion certificate and Title deed

Hi,

  Planning to buy a plot and there is discrepancy between possestion certifcate and the Title deed.

  1. Possession certifcate issued in 1981 by hosing society, shows property as 2800 sqft with NS-70ft and EW-40ft

  Where as

  2. Registered Sale deed from society to the owner/allotee shows the property as  2800 sqft with NS-40ft and EW-70ft, which is in essance correct dimension.

   How important is that these too matches.

prabhu