Seems to me one can do as one pleases subject to the fact that they conform to virtue signalling with narratives being first established to mould opinions & subsequently to curry favour with the majority.
Put another way were India to do this there would be a storm of protests in & outside India particularly in MSM signalling it to be another attack on minority rights. Of course that most EU states having legislated in accordance with the EUSC doesn't preclude them from taking the same jaundiced view of the MSM were India to ban halal for similar if not the same reasons.
Wonder how will UK, current haven of Islamists in Europe, react assuming BJ even contemplates such a move leave alone legislate now that UK isn't part of the EU. @BMD