Section 14(4)(b) in Bihar Contributory Provident Fund Rules, 1948
(b)Interest shall ordinarily be recovered in one instalment in the month after complete repayment of the principal; but, if the period referred to in clause (a) exceeds twenty months; interest may, if the subscriber so desires, be recovered in equal monthly instalments. The method of recovery shall be that provided in sub-rule (2). Payments shall be rounded to the nearest rupees in the manner provided in sub-rule (3) of rule 8.