I speak to Tamils every day. What you're talking about is a polyglot spirituality that borrows from all the neighboring religions. There is no such thing as a Tamil religion. Having asked hundreds of Tamils what their religion was (to fill out applications of their behalf), only one has said to me anything other than "Hindu" , "Christian", or "Muslim". (That one said he didn't have a name for what he believed.)
It is true that, on the Tamil side at least, the war in Sri Lanka is not a religious one, though Tamil Muslims are a separate community from the rest of the Tamils.