(4)No credit under sub-rule (1) shall be available in respect of any amount of foreign tax or part thereof which is disputed in any manner by the assessee:Provided that the credit of such disputed tax shall be allowed for the year in which such income is offered to tax or assessed to tax in India if the assessee within six months from the end of the month in which the dispute is finally settled, furnishes evidence of settlement of dispute and an evidence to the effect that the liability for payment of such foreign tax has been discharged by him and furnishes an undertaking that no refund in respect of such amount has directly or indirectly been claimed or shall be claimed.