How can changes be made in the federal constitution?

In a federal setup, the constitutional jurisdiction of the different organs or levels of the government is constitutionally guaranteed. The process and rules pertaining to making changes in this federal constitution are as follows:

a. the fundamental provisions of the constitution can never be changed unilaterally by one level or tier of the federal government. Consent of both the levels would be required.

b. In the case of India, any changes to the constitution have to be passed by both the Houses of the Parliament with a majority of at least two-thirds. Furthermore, it has to be ratified by the state legislatures of at least half of all the states.