Sometime ago i was reading an article in a gujarati newspaper, which expressed great concern over increasing influence of English over Indian languages and how English words are making several Indian counterparts of theirs extinct.
e.g. “Did you go to the party last night?” is a normal sentence. With Hai na, it would be, “You went to the party last night, Hai na?”
Some bloggers have come up with various possible explanations for the origin of "Hai na". Looking at the context and usage of the term, I can't think of any other origin but Hindi. In Hindi, Hai is a conjugation for third person, for the verb Hona (To be). So, “Hai na?”, would literally mean, “It is. No?”
Listen to this song, from the movie “Jis desh me Ganga Behti hai” (The country, where The Ganges flows). You will definitely enjoy the “Hai na” after every stanza. (Don’t get impatient to listen to Hai na from the word go, wait at least till 00:43 minute).
Na hoy” (Equivalent of an exclamation, like Really?, or Is that so?), will also invade English theasures.
At Languagelog, you can see various other explanations of Hai Na.