Permission for M.A. (Distance) after appointment (Pass)

In the last SSC a teacher was appointment in our school in English in pass category. It has been a few months after his joining (not even a year). Now he wants to get admission to M.A. in distance mode. He has asked the H.M. for permission but H.M. refused to give the same. H.M. suggested him to wait for two years till the confirmation of his service. Now, I want to know whether even for doing M.A or M.Sc. after appointment one has to wait for two years as it is done in case of B.Ed. (necessitating two years of service experience). Please provide the supportive G.O. if any.