The Indian Constitution is both flexible and rigid and has many provisions to modify, add, delete or change it according to the changing needs. An easier method is available for changing the provisions which do not primarily affect the federal system. This has been done in two ways,
1. By providing that the changes in certain constitutional provisions shall not be deemed to be amendments
2. Other provisions are changeable by following an amendment procedure described in Art. 368. (Even this has two categories)
I. A Constitutional Amendment Bill may be initiated in either house of Parliament and if it is passed in each house by
1. a majority (more than 50%) of the total membership of the House must be present on the day of voting
2. and out of those present and voting, at least two-thirds must vote for the bill.
3. If the two conditions are met, the bill is deemed to be passed by the respective House. It goes to the other House thereafter, where the same procedure is repeated. Upon passage in both the Houses, the bill goes to the President for his assent. The bill becomes an act only after getting the presidential assent.
II. However, if an amendment bill seeks to change any provision regarding
A. The manner of Presidential elections.
B. Extent of Executive powers of the Union and the States
C. The Supreme Courts and High Courts.
D. Distribution of legislative powers between the Union and the States and
E. Representation of the States in Parliament,
The amendment bill in such cases is to be ratified by at least 50% of the State Legislatures before the bill goes for Presidential assent. The President cannot refuse assent to a Constitution Amendment Bill unlike the provision in case of ordinary bills. Thus the President is not competent to veto any amendment bill presented to him for assent.
The States in India cannot initiate any bill for constitutional amendment. Notably, a Joint Sitting of the Houses to resolve a deadlock between them in such cases cannot be called in case of amendment bills. In essence, if one house passes an amendment bill and the other house does not, the bill lapses and will have to be introduced afresh to pass it.