Obviously I cannot claim to have read it all, I'm still studying but as far as my knowledge goes, neither SC nor the Constitution
defines who's a Hindu (I'm referring to Hindu as a religion or as a community, not Hindutva as a way of life), except you can find the definition in a few Hindu laws so as to know the group to which that act applies, that's it.
@ashok mourya I get your point, but we were used to be referred to as 'Hindus' when we didn't have our Constitution, in fact we didn't even choose to be called Hindus. The term for it is Indians, or Bharatiya now. Why not use it instead?
Either way, peace everyone