Share Certificate - Cooperative Housing Society

A flat in a Cooperative housing society in Pune has 3 members on their share certificate (A, B & C).A is the son, residing in the USA and is listed No.1 on the share certificate.B and C, are parents and listed as No.2 and No.3The Society needed to increase the share capital, we had to issue additional share certificates to all membersQuestions:n1. Can this additional share certificate be handed over to B & C (without any authorization from A).2. Can B & C sell that property without authorization from A (and request the society to transfer the share certificate in the name of the buyer?).If authorization is required, what documentation will have to be given to the society?nThe Chairman or Secretary have never seen or interacted with A.