I just checked Indian market bitcoin prices, I believe the prices are converging right now. Yes Indian market prices are getting slashed out maybe with the reason of heavy dump from local/international bitcoiners. Usuaally arbitrage trading opportunities are for short-term and this India based opportunity is almost getting finished off.
Yes, converging prices are symptoms of end of possibility of arbitrage trading. But right now Indian market are still trading with enough gaps to make use of. Preev shows $766.7 and Indian exchange unocoin shows prices equivalent of $828.29, more than $50 a good profits to book per one full bitcoin trading instantly.