Section 100(d) in The Chennai Corporation Officers Service Rules, 1975
(d)If qualified and suitable candidate belonging to any of the Scheduled Castes, Scheduled Tribes or the Backward Classes is not available for appointment in the turn allotted for them in the cycle, the turn shall lapse and the vacancy shall be filled by the next turn in the order of rotation. No account shall be taken of any lapsed turns of the Scheduled Castes, the Scheduled Tribes or of the Backward Classes.
