I.R. Coelho v. State of Tamil Nadu (2007) held that —

Constitutional Amendments are changes made to the Constitution of India through a special procedure as laid down in Article 368. India has made over 100 constitutional amendments since 1950. Important amendments include 42nd Amendment (Mini Constitution), 44th Amendment (Fundamental Rights), 73rd Amendment (Panchayati Raj), and 101st Amendment (GST). These are key topics for UPSC and SSC exams.

The Indian Constitution can be amended in three ways: By simple majority in Parliament for certain provisions, By special majority which is 2/3rd majority in both houses under Article 368 for most provisions, and By special majority plus ratification by half the state legislatures for federal provisions. Article 368 governs the amendment procedure.

Most important Constitutional Amendments for UPSC: 1st (reasonable restrictions on FR), 42nd (Fundamental Duties, Directive Principles primacy), 44th (restored original rights), 52nd (Anti-Defection Law), 61st (voting age 21 to 18), 73rd and 74th (Panchayati Raj and Urban Local Bodies), 86th (Right to Education), 101st (GST).

The 42nd Constitutional Amendment (1976) during Emergency is called the Mini Constitution as it made the most changes. Key changes: Added Fundamental Duties (Part IVA), Added words Secular and Socialist to Preamble, Gave Directive Principles primacy over Fundamental Rights, Extended Parliament tenure to 6 years. Many changes were later reversed by 44th Amendment.

The 73rd Constitutional Amendment (1992) gave constitutional status to Panchayati Raj Institutions. The 74th Amendment (1992) gave constitutional status to Urban Local Bodies (Municipalities). Both added new schedules (11th and 12th). They mandated reservation for women (1/3rd) and SCs/STs in local bodies. These are crucial for UPSC and State PSC exams.