Definition amendment expands covered public authorities to include courts and tribunals, broadening GST coverage and administrative reach. The Explanation to Notification No. SRO-GST-13 is amended by substituting the words 'and State Legislatures' with State Legislatures, Courts and Tribunals, thereby expressly including courts and tribunals within the specified category, and this amendment is deemed to have come into force from the first day of March, 2023.