Section 24B(6) in The Rajasthan Co-Operative Service Rules, 1954
(6)Selection for promotion to all other higher post/posts in the State Service shall be made on the basis of merit and on the basis of seniority-cum-merit in the proportion of 50:50.Provided that if the Committee is satisfied that suitable persons are not available for selection by promotion strictly on the basis of merit in a particular year, selection by promotion on the basis of seniority-cum-merit may be made in the same manner as specified in these Rules.Explanation.- If in a service, in any category of post, number of posts available for promotion is an odd number then for purpose of determining the vacancies for selection by promotion on the basis of seniority-cum-merit and merit in the proportion of 50:50, the following cyclic order shall be followed:The first vacancy by seniority-cum-merit:The subsequent vacancy by merit;The cycle to be repeated.