However, where a person who has been sentenced to imprisonment by an order under Section 122 in default of furnishing security is, whilst undergoing such sentence, sentenced to imprisonment for an offence committed prior to the making of such order, the latter sentence shall commence immediately. When a person already undergoing a sentence of imprisonment for life is sentenced on subsequent conviction to imprisonment for a term of imprisonment for life, the subsequent sentence shall run concurrently with such previous sentence.
If any revision or commutation in respect of the earlier term is granted, the new sentence should commence thereafter. Where a second sentence passed on the accused was to commence on the expiration of the first sentence, and the first sentence was subsequently set aside, the second sentence would commence from the date of conviction and the period of imprisonment already undergone in respect of the first sentence would be deemed to have been in respect of the second sentence. In a case where separate trials are held for offences which while constituting distinct offences are inherently or intimately connected with each other, the direction to make the subsequent sentence run concurrently with a previous one has been held to be properly exercised.