Actually Illyushin was at the top of the bid due to its lowest bid price but, officials selected Air Bus due to its low maintenance and fueling costs.
Indian Air Force(IAF) is already operating six IL-78 tankers for mid-air re-fueling and intends to buy new 12 ones. Only six ones are ordered now and remaining six to be ordered later. Either a new bid will be started or the remaining six will also be ordered to the winner of the current bid, that is the Air Bus.
For more info goto => http://www.asian-defence-news.blogspot.in/2012/11/eads-airbus-wins-indian-air-force.html