Tax evasion offences trigger graded imprisonment and fines, with severe offences cognizable and non bailable, and prosecution requiring prior Commissioner sanction. The provision lists offences constituting tax evasion-including invoicing without supply, issuing false invoices, wrongful availment of input tax credit or refund, failure to remit collected tax, falsifying records, obstructing officers, dealing in confiscatable goods, destroying evidence, and abetment. It prescribes graded imprisonment and fines based on the amount involved, mandates a minimum custodial term in higher-value cases unless reasons are recorded, treats certain high-value offences as cognizable and non-bailable while most others are non-cognizable and bailable, requires prior sanction of the Commissioner for prosecution, and defines 'tax' to include related central and integrated GST liabilities and compensation cess.