Section 12(ii) in The Bihar Irrigation and Flood Protection, (Betterment Contribution) Rules, 1961
(ii)Where the sum due to the assessee is not refunded to him within the period prescribed in sub-rule (i) without valid and reasonable cause interest at the rate of four and half per centum per annum shall become payable on such sum from the date of the expiry of the said period of ninety days.
