Where the assessee is a firm, any loss in relation to the assessment year commencing on or before the 1st day of April, 1992, which could not be set-off against any other income of the firm and which had been apportioned to a partner of the firm but could not be set-off by such partner prior to the assessment year commencing on the 1st day of April, 1993, then such loss shall be allowed to be set-off against the income of the firm subject to the condition that the partner continues in the said firm and to be carried forward for setoff under sections 70, 71, 72, 73, 74 and 74A.