Explanation: If the Rajya Sabha declares that it is necessary in the national interest that Parliament should make laws with respect to goods and services tax or a matter in the State List, then the Parliament becomes competent to make laws on that matter.

This provision does not restrict the power of a state legislature to make laws on the same matter. But, in case of inconsistency between a state law and a parliamentary law, the latter is to prevail.

Source: Laxmikanth