Most Authentic source for Getting Total Area under Khasra

Revenue Department aur Town and country planning k online available Map k anusar kise khasre ka area 31000 square feets hai. Patwari 39300 ka area bata raha hai aur keh raha hai k patwari naksha total destroyed condition mai hai per area 39300 hai. Suspected hai k uss khasre mai jyada logo ko jagah de di gai hai. How to get the authentic data. Patwari kya iss tarah ke gadbad kar sakte hai Khasra is located in urban populated area Pls guide