laws of nocs of heirs and their validity

Sir,myself Tanesh my father had three rooms two in housing board maharashtra and one in SRA.He died 8 years ago without making problem is that out of above room,1 mhada room was directly purchased on my elder brother this was done 26 years ago.and in other mhada room we (precisely father mother unmarried sister and me my wife and childern were staying.) now I want to transfer this mhada room on my name.initially my brother and sisiter given noc to society for the transfer of the said room on my name but at final step at the step of giving notice in the news paper to check anybodys objection they stop me from giving advertisement and asking me to first give sister share.when i said if you wish i am ready to transfer SRA room on sis name but if ypu want half share then ask share from elder brother also but for which she is not ready and brother said that father had only two room the room he was staying was purchase by my problem is if i persuade him to give noc for the transfer anf sale of other two room on my and sis name before actual division of the rooms will that noc from himbe valid for the future sale of the room?.Also please guide if i have to take noc for sale and transfer of above mentioned rooms from my other deceased sisiters husband,i will have to take noc from his childern also because my jijai has two sons both major and marreid.?