Even Christians of west perform Hatha yoga. But that doesn't mean that templates like Christianity can be used here. The point is that sources say that the scriptures on which hatha yoga is based are Hindu scriptures (they can't be generalized saying they are Indian scriptures) and hence only Template:Hinduism is apt here. As far as 
my change of template is concerned, then let me ask the blocked editor  first, what explanation he gave for this edit ? -