Rounding of tax amounts adjusts payable and refundable sums to the nearest whole currency unit under specified fractional thresholds. Rounding off requires adjustment of tax, interest, penalty, fine or other payable sums and refunds to the nearest rupee: fractional parts of currency equal to or exceeding fifty paise are increased to the next rupee, and fractional parts below fifty paise are ignored, applying uniformly to liabilities and refunds under the Act.