What do you meant by share certificate as I am belong to chennai and I am not conversant with procedures and regulations followed in the state in which you belong. Clarify
1) As far as Tamilnadu is concern, in respect of flat, here the people would have sale deed for undivided share for land and construction agreement for the built up area.
2) If the flat is allotted by the State Government, the people would have Allottment Letter, Lease Cum Sale Agreement and other correspondance from the State Government. On the completion of the payment of the cost towards the flat, the State Government will register the sale deed in favour of the allottee for both land and built up area.
If your query falls any of the above two, then a Release Deed (it is also called as Relinquish Deed in some states) to be prepared by the Releasor (one who is releasing the property in favour of others) to the Releasee (one or two who are going to be benefited) and typed in a Stamp paper (prescribed amount of stamp duty as per your state) and got to be registered in the Sub Registrar Office. Complete descripttion of the property to be incorporated in the Release / Relinquish Deed and releasing share.