Section 11(4) in The Orissa Municipal Corporation Act, 2003
(4)If any vacancy occurs in the office of the Chairman of any Standing Committee, the Mayor shall convene a meeting of the Committee concerned, as soon as conveniently may be, after the occurrence of the vacancy, for the election of one amongst its members to fill up the vacancy and every Chairman so elected shall continue in office so long as the person in whose place he is elected would have held it, if such vacancy had not occurred.
