Amendment & Miscellaneous
(1) Parliament may, exercising its constituent power, amend any Constitutional provision by addition, variation, or repeal, per this article's procedure. (2) An amendment starts as a Bill in either House, needing a majority of that House's total membership plus a two-thirds majority of those present and voting in each House - then goes to the President for assent, after which the Constitution stands amended. Amendments touching specific entrenched provisions (President/VP election, Union executive power, High Court powers, Union-State legislative relations, Seventh Schedule Lists, state representation in Parliament, or this article itself) additionally need ratification by at least half the State Legislatures before presidential assent. (3) Article 13 doesn't apply to amendments under this article. (4)-(5) [Added by the 42nd Amendment, 1976; both later declared unconstitutional by the Supreme Court in Minerva Mills v. Union of India, 1980] purported to bar all judicial review of amendments and declare Parliament's amending power unlimited.
This is the master procedure for amending India's Constitution - requiring a special (not ordinary) majority in Parliament, and for the most fundamental structural provisions, ratification by half the states too. Crucially, this article is also the site of one of Indian constitutional law's most important doctrines: in Kesavananda Bharati v. State of Kerala (1973), a 13-judge Supreme Court bench held that Parliament's amending power under Article 368, though very broad, CANNOT alter the Constitution's "basic structure" (core features like democracy, secularism, judicial review, and federalism) - and when the 42nd Amendment later tried to legislate around this by declaring there was NO limit on amending power and no judicial review of amendments, the Supreme Court struck those specific additions down in Minerva Mills v. Union of India (1980) as themselves violating the basic structure doctrine.
The "basic structure doctrine" from Kesavananda Bharati is why, even though Parliament has amended the Constitution over 100 times using this article's procedure, no amendment can ever validly abolish things like judicial review, free and fair elections, or the Constitution's secular character - these are treated as permanently beyond even Parliament's constituent amending power.