The Constitution of India, 1950
If at any time it appears to the President that the public interests would be served by the establishment of a Council charged with the duty of— (a) inquiring into and advising upon disputes which may have arisen between States; (b) investigating and discussing subjects in which some or all of the States, or the Union and one or more of the States, have a common interest; or (c) making recommendations upon any such subject and, in particular, recommendations for the better co-ordination of policy and action with respect to that subject, it shall be lawful for the President by order to establish such a Council, and to define the nature of the duties to be performed by it and its organisation and procedure.