If it's intended to be a romanization of ね, then yes, "ne" is more common. Alternatively it could be a reference to Ender's Game, where "neh" is used in the same way.
What is the meaning of the Chinese (?) symbol?
(I've just started learning Mandarin, and enjoy looking at the origin of words and characters.)
"Innit" is slang in Britain, used at the end of a sentence. It doesn't have to mean "isn't it", but could be "aren't you", "won't you" etc.