Section 50C(5) in The Mumbai Municipal Corporation Act, 1888
(5)In the event of the office of Chairman falling vacant previous to the expiry of his term the committee shall, as soon as conveniently may be after the occurrence of the vacancy, appoint one of their member being a councillor, to fill such vacancy and the Chairman so appointed shall hold office so long only as the person in whose place he is appointed would have held it if such vacancy had not occurred.
