Section 41(1) in The Bihar Finance Service Rules, 1953
(1)Promotion to the rank of the Deputy Commissioner of Commercial Taxes shall be made from amongst the Assistant Commissioner of Commercial Taxes who have put in eight years of total continuous service from their first appointment as Commercial Taxes Officer on the basis of seniority-cum-merit, so however, that due representation in promotion to the rank of the Deputy Commissioner of Commercial taxes is accorded to the officers belonging to Scheduled Castes and Scheduled Tribes in accordance with Government orders issued in this behalf from time to time:Provided that the above period of service shall be reduced by one year in the case of officer's belonging to Scheduled Castes and Scheduled Tribes if adequate numbers of officers of these castes with prescribed minimum length of service are not available in the required promotion for the purpose of this sub-rule.
