constitutional provisions have to be harmoniously construed and understood so as to avoid making any provision nugatory and redundant. If the list of Scheduled Castes/Scheduled Tribes in the Presidential Orders under Articles 341/342 is subject to alteration only by laws made by Parliament, operation of the lists of Scheduled Castes and Scheduled Tribes beyond the classes or categories enumerated under the Presidential Order for a particular State/Union Territory by exercise of the enabling power vested by Article 16(4) would have the obvious effect of circumventing the specific constitutional provisions in Articles 341/342. In this regard, it must also be noted that the power under Article 16(4) is not only capable of being exercised by a legislative provision/enactment but also by an Executive Order issued under Article 166 of the Constitution. It will, therefore, be in consonance with the constitutional scheme to understand the enabling provision under Article 16(4) to be available to provide reservation only to the classes or categories of Scheduled Castes/Scheduled Tribes enumerated in the Presidential Orders for a particular State/Union Territory within the geographical area of that State and not beyond. If in the opinion of a State it is necessary to extend the benefit of reservation to a class/category of Scheduled Castes/Scheduled Tribes beyond those specified in the Lists for that particular State, constitutional discipline would require the State to make its views in the matter prevail with the central authority so as to enable an appropriate parliamentary exercise to be made by an amendment of the Lists of Scheduled Castes/Scheduled Tribes for that particular State. Unilateral action by States on the touchstone of Article 16(4) of the Constitution could be a possible trigger point of constitutional anarchy and therefore must be held to be impermissible under the Constitution.”
