You need to request Commissioner u/s 119(2)(b) of the Income tax Act 1961 to condone delay in filing revised return. Once permission is received, you need to file revised return with accrued Interest Income. Since you have already received the refund, CPC will issue intimation u/s 143(1) and raise demand in the intimation as you would have received excess refund. You can pay the outstanding demand raised and the matter will be solved.