CANCELLATION OF FAMILY MEMBER CERTIFICATE

My father in law has two wifes and he has 3 daughters, first wife expired when my wife age was 4 months later my father in law got married her own sister. My father in law expired Mar 2020 due to algemra health issue they said. Later my wife went to vizag after covid. They applied family member certificate without my wife signature and supporting documents. Thahisldar rejected first time. Later my signed in application form and submitted then got family member certificate. What are the properties, Insurences and fixed deposits they withdraw without wife signature, later we applied what are documents they provide to apply family member certificate was asked in RTI, my mother in law mentioned my father in law has only one wife and my wise is also her daughter. Hence my wise approached spandana to cancel the Family member certificate due to wrong information provided. but thasidar is not accepted due to they recommended on government official not cancel. what can we do to cancel FMC