Article 253 of Constitution of India "Legislation for giving effect to international agreements"
Notwithstanding anything in the foregoing provisions of this Chapter, Parliament has power to make any law for the whole or any part of the territory of India for implementing any treaty, agreement or convention with any other country or countries or any decision made at any international conference, association or other body.
Article 254 of Constitution of India "Inconsistency between laws made by Parliament and laws made by the Legislatures of States"
(1) If any provision of a law made by the Legislature of a State is repugnant to any provision of a law made by Parliament which Parliament is competent to enact, or to any provision of an existing law with respect to one of the matters enumerated in the Concurrent List, then, subject to the provisions of clause (2), the law made by Parliament, whether passed before or after the law made by the Legislature of such State, or, as the case may be, the existing law, shall prevail and the law made by the Legislature of the State shall, to the extent of the repugnancy, be void.
(2) Where a law made by the Legislature of a State with
respect to one of the matters enumerated in the concurrent
List contains any provision repugnant to the provisions of
an earlier law made by Parliament or an existing law with
respect to that matter, then, the law so made by the
Legislature of such State shall, if it has been reserved for
the consideration of the President and has received his
assent, prevail in that State:
Provided that nothing in this clause shall prevent
Parliament from enacting at any time any law with respect to
the same matter including a law adding to, amending, varying
or repealing the law so made by the Legislature of the
State.