Section 12(2)(c) in The M.P. Civil Services (General Conditions of Services) Rules, 1961
(c)In the case of a person who is initially taken on deputation and absorbed later (i.e. where the relevant recruitment rules provide for "transfer on deputation/transfer") his seniority in the grade in which he is absorbed will normally be counted from the date of absorption. If he has however been holding already (on the date or absorption) the same or equivalent grade on regular basis, in his parent department, such regular service in the grade shall also be taken into account in fixing his seniority, subject to the condition that he will be given seniority, from the date he has been holding the post on deputation or the date from which he has been appointed on a regular basis to the same or equivalent grade in his present department whichever is later.