The All India Services (Discipline And Appeal) Rules, 1969
RULE 16. Orders against which appeal lies:
Government of India's Decisions
IPS Officers serving with the Government of India on deputation or their Heads of Departments should not enter into direct correspondence with the State Government or the Inspector General of Police concerned on matters relating to service conditions. The correspondence in this regard should invariably be between the borrowing and the lending Government. Representations from such officer are, therefore, to be routed through the Ministry of Home Affairs and not sent to the State Government or the Inspector General of Police of the State.
[G.I., M.H.A. letter No. 13/4/61-P(V) dated 5th May,1961]