Stamp duty

One co-operative housing society registered in 1969 in Gujarat and allotted a flat to its member and issued share certificate and allotment letter, later that member transferred the same flat to some other person in 1978 without registering a sale deed. Now, question is whether the transaction of resale made by the first allotee to other person is exempt to pay stamp duty? or it is must to register sale deed with duly stamped.