Builder Has Given Dastavge After Death Of Owner

Hello sir, I am from Gujarat, India, my father has purchase property in 1990. Society is develop in 1988. Land where society is developed there are 4 owner and all of them give power of attorney to 4th person, in 1989 with the signature of 4 society develop and build houses. In 1998 document registration done (Dastavage) in the signature of 4th owner. 2nd owner death in 1996. So, their child are disputed to case document are illegal because 2nd owner death in 1996 his power of attorney null and void in 1998. How can register property document (Dastavage). In 2018 they oppose in registrar office. 1) Half of society get property card while some have facing this issue. 2) This is a fault of registrar who has to check the owner ship. 3) I have read one case where this matter is civil not for registrar office (Collector office) I have a doubt: Is there any low or judgment related to this matter. i.e. document valid after 20 years or any think else