(1)An assessee, being a resident shall be allowed a credit for the amount of any foreign tax paid by him in a country or specified territory outside India, by way of deduction or otherwise, in the year in which the income corresponding to such tax has been offered to tax or assessed to tax in India, in the manner and to the extent as specified in this rule :Provided that in a case where income on which foreign tax has been paid or deducted, is offered to tax in more than one year, credit of foreign tax shall be allowed across those years in the same proportion in which the income is offered to tax or assessed to tax in India.