The federation is a union because it is indestructible and helps to maintain the unity of the country.Art 155 and 156 provide that the Governor, who is the constitutional head of a State, is to be appointed by the President and stays only until the pleasure of the President The Centre may take over the administration of the State on the recommendations of the Governor or otherwise.It can declare a law as unconstitutional, if it contravenes any provision of the Constitution.

A unitary system is governed constitutionally as one single unit, with one constitutionally created legislature. A unitary state is a sovereign state governed as one single unit in which the central government is supreme and any administrative divisions (sub national units) exercise only powers that the central government chooses to delegate.

This is one of the federal features of the Indian constitution.

The federal polity, in other words, provides a constitutional device for bringing unity in diversity and for the achievement of common national goals. A federal government exists when the powers of the government for a community are divided substantially according to a principle that there is a single independent authority for the whole area in respect of some matters and there are independent regional authorities for other matters, each set of authorities being co-ordinate to and subordinate to the others within its own sphere.

The Constitution of India has adopted federal features; though it does not, in fact, claim that it establishes a federation.

The supremacy of the constitution means that both, the Union and the State Governments, shall operate within the limits set by the Constitution.

And both the union government and the central government derive their powers from the constitution.: The constitution of India is a rigid constitution and this is one of the basic features of federal constitution.The question whether the Indian Constitution could be called a federal constitution troubled the minds of the members of the Constituent Assembly.This question cannot be answered without going into the meaning of federalism and the essential features that are evident in federal state.In other words, Governor is the agent of the Centre in the States.The working of Indian federal system clearly reveals that the Governor has acted more as centre’s representative than as the head of the State.The following provision of Indian constitution makes it unitary Article I of the Constitution describes India as a ‘Union of States’, which implies two things: firstly, it is not the result of an agreement among the States and secondly, the States have no freedom to secede or separate from the Union.