What is the power of Parliament to legislate for two or more states by consent and adoption?
The power of Parliament to legislate for two or more states by consent and adoption is as follows:

If it appears to the Legislatures of two or more States that any matter with respect to which Parliament has no power to make laws for the States except as provided in articles 249 and 250 should be regulated in such States by Parliament by law, and if resolutions to that effect are passed by all the Houses of the Legislatures of those States, it shall be lawful for Parliament to pass an act for regulating that matter accordingly. Any Act so passed by Parliament may be amended or repealed by an Act of Parliament passed or adopted in like manner but shall not, as respects any State to which it applies, be amended or repealed by an Act of the Legislature of that State.