Reduction of interest where tax is reduced by specified orders; excess interest refundable and officer may reduce or waive interest. Where an order under sections 154, 155, 250, 254, 260, 262 or 264 reduces the tax on which interest was payable under clause (iii) of the proviso to sub section (1), the interest shall be reduced accordingly and any excess interest paid shall be refunded; additionally, the Income tax Officer may, in prescribed cases and circumstances, reduce or waive interest payable under any provision of Section 139 notwithstanding that proviso.