(b)the case may at any time, and shall at intervals of not more than three months, be reconsidered by the Central Government or committing authority or the prescribed officer, and if on any such reconsideration it appears to the Central Government or committing authority or such prescribed officer that the conduct of the offender since his conviction has been such as to justify a remission of the sentence, the Central Government or committing authority or such prescribed officer shall remit the whole or any part of it;