RUH to Mumbai , in a B747-400, at LRC should take no more than about six hours and if empty would have the capacity to carry up to twelve hours worth of fuel, various limitations permitting. In an empty aircraft at 270kts and FL220 fuel consumption should not be excessive. Gear down ferry flights in the B744 are not considered a problem. A few numbers, all engines operating, trip distance 2000 miles, nil wind, fuel required for long range cruise approx 80 tons.
Maybe there is more to this than we are being told?