Explanation:

The Parliament can make laws on the subjects mentioned in the State List in the following circumstances:
1. When a resolution is passed by the Rajya Sabha by two-thirds majority making it lawful for the Parliament to legislate on a subject mentioned in the State List in national interest (Art.249).
2. When a proclamation of emergency is in operation, the Parliament has the power to make laws for the whole or any part of India on any of the matters stated in the State List (Art.250).
3. When two or more States give their consent and pass resolutions for the same in their respective Legislatures to enable the Parliament to make a law on any matter listed in the State List (Art.252). Any such law will be applicable to only those States which have passed such resolution, not to all states.
4. The Parliament has the power to make laws for the whole or any part of India for implementing any treaty, agreement or convention with any other country or any decision made at any international conference etc. (Art.253)