When any person subject to this Act has been convicted by an Assam Rifles Court of any offence, the Central Government or the Director-General, or in the case of a sentence which he could have confirmed or which did not require confirmation, an officer not below the rank of Deputy Inspector-General within whose command such person at the time of conviction was serving or the prescribed officer may,—
         (a) either with or without conditions which the person sentenced accepts, pardon the person or remit the whole or any part of the punishment awarded; or
         (b) mitigate the punishment awarded; or
         (c) commute such punishment for any less punishment or punishments mentioned in this Act; or
         (d) either with or without conditions which the person sentenced accepts, release the person on parole.