Penalty for assessment under sec 63

The proper office to issue an assessment order in Form GST ASMT-15 with in 5 years from the date specified under Section 44 for furnishing of the annual return for the financial year to which the tax not paid relates.

Order of Provisional attachment

The commission may during the pendency of any proceeding under section 63, pass an order in Form GST DRC-22, to attach any property including bank account belonging to taxable person provisionally to protect the interest of the revenue. (Section 80 of CGST Act)

Offences or Penalties in case of non-compliance with Provision

Section 122(xi) of CGST Act, where a taxable person, is liable to be registered under this Act but fails to obtain registration.

Such person shall be punished with a penalty that shall be higher of the amount of tax evaded or Rs. 10000 whichever is higher.

Under Section 63 , the person whose registration has been cancelled u/s 29(2) of CGST Act but who was liable to pay tax , the proper officer can excercise jurisdiction over such person & can proceed to assess the tax liability of such person to beat of his judgement. for relevant tax period.
Note : Section 63 starts with words " notwithstanding anything to contrary in section 73, 74" this the provision of Best judgement assessment have overriding effect over the provision of demand & recovery ( Section 73,74)