Previous sanction requirement restricts cognizance of GST offences and limits trial to higher magistracy only. Cognizance of offences under the Act is conditioned on prior executive approval: no court may take cognizance of offences punishable under the Act or the rules without the previous sanction of the Commissioner, and no court inferior to a Magistrate of the First Class shall try any such offence, thereby imposing a pre cognizance sanction requirement and a minimum magistracy threshold for trial.