(1) When a person already undergoing a sentence of imprisonment is sentenced on a subsequent conviction to imprisonment or imprisonment for life, such imprisonment or imprisonment for life shall commence at the expiration of the imprisonment to which he has been previously sentenced, unless the Court directs that the subsequent sentence shall run concurrently with such previous sentence:
Provided that 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.
(2) When a person already undergoing a sentence of imprisonment for life is
sentenced on a subsequent conviction to imprisonment for a term or imprisonment
for life, the subsequent sentence shall run concurrently with such previous
sentence.
Code of Criminal Procedure (CrPC)
421 CrPC Warrant for levy of fine
422 CrPC Effect of such warrant
424 CrPC Suspension of execution of sentence of imprisonment
425 CrPC Who may issue warrant
426 CrPC Sentence on escaped convict when to take effect
427 CrPC Sentence on offender already sentenced for another offence