The seniority shall be determined in accordance with the quota rule to the posts available in the respective years in which the vacancies had arisen otherwise existing substantive posts should be filled up applying Rule 6.It is,therefore,incumbent upon the State Government to find out how many vacancies were existing in the year 1974-75 and thereafter every year and to determine as to how the respective posts stood reserved for the direct recruits and promotees in accordance with the quota