Share certificate in cooperative housing society

Dear Sir,

Myshelf is owing 1000 sq. ft flat in co-operative housing society in mumbai ( flat is in the joint name of myshelf & my wife). The building is going under redevelopment & I do not need such big flat & I am askiing developer & soecity to provide me 500 sq ft of 2 flat. One flat on my name & other flat on my wife name. Is it possible as per the law ?

Thanks