In the context of the Indian Constitution, particularly under Article 368, certain amendments require a special procedure for ratification beyond just approval by Parliament. When an amendment affects important provisions such as Articles 54, 55, 73, 162, 241, or any of the lists under the Seventh Schedule, it necessitates additional validation.
The requirement is that the amendment must be ratified by at least one-half of the State Legislatures. This stipulation ensures that changes with significant impact on the federal structure or foundational elements of governance have broader consensus among the states, reflecting the diverse federal nature of India.
Thus, the extent of ratification required for such amendments is: Not less than one-half of the State Legislatures.