Partition deed

Hello Sir, I would like to seek your advise where in the said property belongs to my father in law, deceased in the year 2002, still the property remain on his name, all property taxes paid and updated till date is on his name, however her wife and her 3 daughter now like to have a partition deed among themselves. The building consist of ground floor and first floor. No deed has been made by my father in law before he deceased in respect to property segregation among his family members. however the elder sister claim the 1st floor and the middle sister claim the ground floor and for my wife she is the youngest would like to claim the roof right so that she can construct accordingly the KMC approved covered area if at all permitted. However we are not sure if at all the KMC will give us the authorization to construct the 2nd floor, her 2 sister is asking for a partition deed to get happen before they allow my wife to get the construction happen. What do you advise? Similarly they would like my mother in law to gift her 1/4th share among her 3 daughter during the partition deed. Please advise accordingly or should we wait for complete demolition of the property and then claim as per my wife legal rights.