Traffic X & Call signs

I don't think I can give you a complete reply, but I can provide some information.  TrafficX does not provide updates to the allowable callsigns.  But the aircraft, in most cases have correct, or semi correct callsign info in their aircraft.cfg files.  But, a workable version of Editvoicepak does exist.  I have installed it on my FSX system and it works great.  It does include Kingfisher in its available callsigns.  You can find it at the Editvoicepak website:
http://www.fsonline.dk/en/index.php?title=EditVoicepack

However, I am not sure that will completely satisfy you.  I did a little looking at my TrafficX system and I am not sure what it provides in the way of AI flightplans and Aircraft for Kingfisher.   The airline does appear in the list of selectable airlines in the TCC's Flight Plans menu, but when you select it, it shows no existing flight plans.  It also shows up in the menu of selectable airlines in the Trafic Movements section of the TCC and on my system, the check box for it is checked so you may be able to generate flight plans for Kingfisher.  But I did a quick check to see what Kingfisher aircraft were available by searching for a KFR parking code and only an ATR42 showed up, and that was for some other airline.  So there might be Kingfisher aircraft, but I didn't find one on my very quick search.