Redevelopment

Hi, Our Society is Co-Op. Hou.Soc.Ltd and registered on 1980 in Registrar Office, Gujarat. our society made Tenement, Bungalows, Raw Houses and flats also. Tenement members - 15 Bunglows Members - 5 Raw Houses Members - 20 Block A to L each block 12 unit so Flats Members - 144 Total members of Society are 184 members and society give a share certificate to all members and plan pass also in Society name. (1) if Block No. A to L members ready for redevelopment work and they all are agree so the maximum above 75% members are ready for redevelopment work. My Question is :- (1) 75% members are ready for redevelopment then we can proposed developer to redevelopment whole society? (2) If Tenement, Bungalows and Raw Houses members (40 members) are not agree for redevelopment work then what can we doing or give us advise it's possible and how can? Note :- Society is very old so structure is very weak and it's necessary to redevelopment. Place - Ahmedabad, State - Gujarat. Thank You