Article 249 of Constitution of India "Power of Parliament to legislate with respect to a matter in the State List in the national interest"
(1) Notwithstanding anything in the foregoing provisions of this Chapter, if the Council of States has declared by resolution supported by not less than two-thirds of the members present and voting that it is necessary or expedient in national interest that Parliament should make laws with respect to any matter enumerated in the State List specified in the resolution, it shall be lawful for Parliament to make laws for the whole or any part of the territory of India with respect to that matter while the resolution remains in force.
(2) A resolution passed under clause (1) shall remain in
force for such period not exceeding one year as may be
specified therein:
Provided that, if and so often as a resolution approving the
continuance in force of any such resolution is passed in the
manner provided in clause (1), such resolution shall
continue in force for a further period of one year from the
date on which under this clause it would otherwise have
ceased to be in force.
(3) A law made by Parliament which Parliament would not but for the passing of a resolution under clause (1) have been competent to make shall, to the extent of the incompetency, cease to have effect on the expiration of a period of six months after the resolution has ceased to be in force, except as respects things done or omitted to be done before the expiration of the said period.
Article 250 of Constitution of India "Power of
Parliament to legislate with respect to any matter in the
State List if a Proclamation of Emergency is in operation"
(1) Notwithstanding anything in this Chapter, Parliament
shall, while a Proclamation of Emergency is in operation,
have, power to make laws for the whole or any part of the
territory of India with respect to any of the matters
enumerated in the State List.
(2) A law made by Parliament which Parliament would not but
for the issue of a Proclamation of Emergency have been
competent to make shall, to the extent of the incompetency,
cease to have effect on the expiration of a period of six
months after the Proclamation has ceased to operate, except
as respects things done or omitted to be done before the
expiration of the said period.