States can never make laws on subjects that Parliament also touches.

States can legislate on Concurrent List subjects too, but if their law conflicts with a Union law, the Union law usually prevails unless the President has approved the state law specifically (Article 254).

Article 246 lets Parliament override all state powers whenever it wants.

Parliament's exclusive power is limited to the Union List; for the State List, States have exclusive power except in Union Territories or during specific constitutional situations (like Article 249 or 250).

The Constitution of India

Article 246

Subject-matter of laws made by Parliament and by the Legislatures of States

(1) Notwithstanding anything in clauses (2) and (3), Parliament has exclusive power to make laws with respect to any of the matters enumerated in List I in the Seventh Schedule (in this Constitution referred to as the “Union List”).§

(2) Notwithstanding anything in clause (3), Parliament, and, subject to clause (1), the Legislature of any State also, have power to make laws with respect to any of the matters enumerated in List III in the Seventh Schedule (in this Constitution referred to as the “Concurrent List”).§

(3) Subject to clauses (1) and (2), the Legislature of any State has exclusive power to make laws for such State or any part thereof with respect to any of the matters enumerated in List II in the Seventh Schedule (in this Constitution referred to as the “State List”).§

(4) Parliament has power to make laws with respect to any matter for any part of the territory of India not included in a State notwithstanding that such matter is a matter enumerated in the State List.§

Why this exists

India's Constitution-makers wanted a strong federal structure with a clear division of powers to avoid disputes between the Centre and States, learning from federal systems like Canada and Australia. The Seventh Schedule's three lists, combined with Article 246, were designed to prevent overlapping claims and ensure smooth governance, while still allowing the Union government primacy in matters of national importance.

How courts read it

Courts have developed the 'doctrine of pith and substance' to decide which list a law truly falls under when its subject seems to overlap categories, as seen in cases like State of Bombay v. F.N. Balsara (1951). In cases of conflict between Union and State laws on the Concurrent List, courts have applied Article 254 alongside Article 246, as in cases such as M. Karunanidhi v. Union of India (1979), affirming that the Union law prevails unless the State law has received Presidential assent for a specific state.

Common misconceptions

Myth: States can never make laws on subjects that Parliament also touches.
Fact: States can legislate on Concurrent List subjects too, but if their law conflicts with a Union law, the Union law usually prevails unless the President has approved the state law specifically (Article 254).
Myth: Article 246 lets Parliament override all state powers whenever it wants.
Fact: Parliament's exclusive power is limited to the Union List; for the State List, States have exclusive power except in Union Territories or during specific constitutional situations (like Article 249 or 250).