Judgment :- R. JAYASIMHA BABU, J. We do not find any merit in the petition. Amittedly, no period of limitation had been fixed by the statute or the rules made thereunder. At the time the credit was taken there was no dispute about the fact that the materials had in fact been received and the duty had been paid thereon. The limitation prescribed subsequently by notification was not given retrospective effect. The Tribunal was right in holding that the credit taken beyond six month's period is perfectly valid. 2.The petition is dismissed.