Indian Polity / Centre State Relations
Article 368 talks about the procedure of amendment of Indian Constitution. Amendment of the Constitution of India includes, (i) Adding or inserting a new Article, (ii) Deletion of an Article (added Article is deleted), (iii) Repealing an Article (if original Article is deleted) and (iv) Alteration of an Article. The amendment procedure of Indian constitution is borrowed from the constitution of South Africa.
The procedure to amend the Indian constitution is somewhat rigid and flexible. Article 368 of the Indian Constitution provides only two types of amendment procedures. However in India, 3 procedures are followed. They are
There are certain Articles, PARTS and Schedules which are amended by the Parliament with a simple majority. That means half the members or above, present and vote just like an Amendment of ordinary law.
Any Amendment that is made to the Constitution by simple majority is not deemed to be Amendment under Article 368 because there is no much difference in Amendment of ordinary law and certain parts of the Constitution.
Examples like Creation and the Abolition of States, Parliamentary procedures, Ways of Acquiring Citizenship, Delimitation of Constituencies, etc. are amended with simple majority.
Some PARTS of the Constitution like PART III, PART IV and all other parts which are not covered in first and third procedures are amended with special majority. It is the majority in which 2/3rd members present and voting plus majority of total membership of each individual House.
For example, if the total strength of Lok Sabha is 545, 2/3rd members present and voting should be greater than 273 which is just above the halfway mark of 545.
Let us say, in total 400 members were present in Lok Sabha at the time of making the Amendment, in which 275 supported and 125 opposed the move. In this case, the Amendment is deemed to be passed because 275 out of 400 is greater than 2/3rd majority and at the same time 275 is greater than 273.
It is also special majority of the Parliament with 2/3rd members present and voting plus majority of total membership of each individual House of the Parliament and at the same time ratification with simple majority by more than half of the State Legislatures.
If there exists an Upper House in a State, even the Upper House has to ratify it. The State Legislatures must have to ratify the Bill within the time duration specified by the President. If less than half the states ratify it, the Bill is deferred and it will be sent back to the States which rejected it.
If a State said "No" it can say "Yes" later. But "Yes" state cannot say "No" later. Examples like Federal and Interstate relations, Representation to States in Parliament, Universal Adult Franchise, Procedure of the election of President of India, Article 368 of Indian Constitution itself, etc. are all amended with this procedure.