The question is largely a regulatory one. Dubai Internet City hops their traffic off to the PSTN to the best of my knowledge and does not provide “toll arbitrage” type services. This basically looks like a large campus based pbx to the PSTN.
Since this is the case, it leads me to believe that it is _probably_ illegal to pass traffic via IP without giving the PTT in India the proper toll. You definitely should check with a lawyer that deals with Telecom regulations in that region though.