Well, it is an English word. I've heard and read it often, and I was surprised that Anu had lakh as AWAD, but not its sibling crore. I myself have never used crore in speech, except jocularly during the dot-bomb with Indian programmers, but found myself using (and having to understand) lakh when discussing my friend Krishnan's wedding (or the cost thereof) with his older brother Ganapati. Add to this that I am fascinated by the other Englishes of the world besides those of the States/Canada and the UK/Ireland. For example, African and Indian English.