This is fascism. It uses religion as a convenient part of their "culturally pure" state ideology. It's a more basic sociological ingroup/outgroup reaction than anything to do with religion. https://en.wikipedia.org/wiki/Hindutva
The definition and the use of Hindutva and its relationship with Hinduism has been a part of several court cases in India. In 1966, the Chief Justice Gajendragadkar wrote for the Supreme Court of India in Yagnapurushdasji (AIR 1966 SC 1127), that "Hinduism is impossible to define".[30][b] The court adopted Radhakrishnan's submission that Hinduism is complex and "the theist and atheist, the sceptic and agnostic, may all be Hindus if they accept the Hindu system of culture and life".