<h1>Constitutional mandate requires GST implementation; failure causes loss of tax-levying entitlement and a potential fiscal gap.</h1> The constitutional amendment mandates GST implementation by the specified deadline, making deferral legally impermissible because failure to enact GST would terminate the government's entitlement to collect existing indirect taxes. The GST Council, acting by consensus, has set implementation rules and tax-rate brackets, while state legislatures are required to pass SGST bills; non-joining states risk double taxation and competitive disadvantages. The Council remains open to rate adjustments and expects operational issues to be resolved over time.