I've met multiple Patel families, and I'm in Britain, but that doesn't invalidate "Patil". I think it's kinda like the difference between Smith and Smythe, except I don't think either Patil or Patel is as ridiculously pretentious as "Smythe". I don't know the language, so don't take my word for it, I'm just guessing.

Anyone ever think that maybe Rowling gave the characters names like that because, well ... PEOPLE DO HAVE NAMES LIKE THAT? Hell, for all we know, Cho might be white and have really ignorant whatever-the-Chinese-ish-equivalent-of-Wapanese-is parents ... nah, born two decades too early, wasn't she?