Section 7(2) in The Indian Post Office Rules, 1933
(2)For clearance through the Customs, a fee, recoverable from the addressee, at the rate of thirty rupees if released after levying customs duty for each foreign letter packet or insured box and at the rate of thirty rupees for each foreign parcel or bulk bag of printed matter which weights more than 500 grams, each imported by post into India on which Import customs duty is payable shall be levied.Vide GSR 860 (E) dated 12th December 1994
