My father deceased property card on me and mother name

Dear Sir/Madam, I have written to your Mumbai City Collector at least 07 times ,& he is unable to reply a simple response to a simple question which I have asked him . I have some land in Mahalaxmi –Mumbai .My father died in 1987 where there was a property card with his remaining 05 siblings names on it ,I was told that to add my mother & my name on property card It will cost us Rs80,000 .Which after checking with my “various sources “ did not find true and was told only Furnish my father death certificate .Please can you look into and revert to me at the soonest & ask your collector to reply to me I want my response by today evening as I should not have to send an email 07 times for a simple question. Best Regards, Zubin Vakil