GST rate amendments update tariff classifications and product descriptions, reallocating goods across state SGST rate categories. Amends the Mizoram State Tax (Rate) notification to substitute, insert and omit tariff codes and descriptive entries across Schedules I-IV, aligning specific goods with revised SGST rate categories of 2.5%, 6%, 9% and 14%, and specifying that these amendments take effect from 1 January 2022.