You should be OK with any 19" rim compatible with the X6. I had the 214 Y spoke 20's on my 2010 and ran (forgot the number) 19" Star Spokes for the winter setup that I believe are 19x8.5. I also had the 2010 Sport package with Adaptive Drive and experienced no issues, the car drives a lot better on snow tires on the 19's here. In Colorado!
2013 X6 50i with Luxury seating, HUD, Premium Package, Premium Sound, Cold Weather Package, Space Saver Spare,3 seats, BMW Apps.
Former "10 X6 35i, Space Grey, Cold Weather, Sport Package with 20",Sport Activity Package, Premium, Comfort Seats, Technology Package. (Buyback)
Former '04 X5 4.4i,
Former '03 X5 3.0 (Stolen)
Former '01 X5 3.0 (Lemoned)
Former 1998 Range Rover 4.6HSE
Former 1995 Isuzu Trooper LS 3.0