Section 107A(2) in The Indian Post Office Rules, 1933
(2)If the addressee of (a) an inward foreign value-payable packet (or bag) of printed papers or business papers, or (b) an inward foreign value-payable insured letter addressed "Poste Restante" fails to take delivery of it within seven days following the date of its arrival in the office of delivery, and if it weighs more than 500 grams, a warehousing charge at the rate of rupee one per day commencing on the eighth day shall be collected from the addressee at the time of delivery.