"Hindutva" can be translated as Hindu extremism or Hindu supremacy. Materially, what this ideology is calling for is the creation of a Hindu ethno-state where minorities, especially Muslims, and then to a degree Christians as well, are reduced to second class citizens. In some cases, people call for their citizenship to be removed completely, or for them to be genocided and to be violently exterminated from India. On top of all this, the call is to essentially dismantle India's democracy. So there's a lot at stake here.