adverse possession

My grandmother had bought a land register --ered on her name on 9 th June 1936.in that deed the seller wrote wrong plot no and area.but in the deed the chauhaddi or boundaries were right and we had possession in it(pucca house from 79 years,had tenants,paid electricity bills,water tax etc).but since plot no was wrong we had been regularly paying tax of the other plot which was 720 sq ft less in size. Now the third generation of the seller is claiming.can he have any legal right.or can both parties if agreed file rectification deed.