Section 23(4)(iii) in The U.P. Food and Civil Supplies (Weights and Measures) Service Rules, 1981
(iii)Where, in accordance with the rule or prescribed procedure, the unfilled vacancies from any source could, in the circumstances mentioned in the relevant rule or procedure be filled from the other source and appointment in excess of quota are so, made, the persons so appointed shall get the seniority of that very year as if they are appointed against the vacancies at their quota.