law: 135. Execution of sentence of imprisonment.-
  (1) Whenever any sentence of imprisonment is passed under this Act by a Force Court or whenever any sentence of death is commuted to imprisonment, the confirming officer or in case of a Summary Force Court the officer holding the Court or such other officer as may be prescribed shall, save as otherwise provided in sub-sections (3) and (4), direct that the sentence shall be carried out by confinement in a civil prison.
  (2) When a direction has been made under sub-section (1), the commanding officer of the person under sentence or such other officer as may be prescribed shall forward a warrant in the prescribed form to the officer in charge of the prison in which such person is to be confined and shall arrange for his dispatch to such prison with the warrant.
  (3) In the case of a sentence of imprisonment for a period not exceeding three months and passed under this Act by a Force Court, the appropriate officer under sub-section (1) may direct that the sentence shall be carried out by confinement in Force custody instead of in a civil prison.
  (4) On active duty, a sentence of imprisonment may be carried out by confinement in such place as the officer not below the rank of Additional Deputy Inspector-General within whose command the person sentenced is serving or any prescribed officer may from time to time appoint.