Rule-making power under GST law includes retrospective rules and penalty provisions for contravention. The Government may, on the Council's recommendations and by notification, make rules for carrying out the provisions of the Integrated Goods and Services Tax Act, 2017. The rule-making power includes matters required or permitted to be prescribed by rules, and may extend to rules with retrospective effect, subject to the Act's commencement date. Rules may also provide for a penalty not exceeding ten thousand rupees for contravention.