These are the Ukraine government stats for the eleventh day of the war, which you can retrieve at the URL below. They look plausible to me. But it's a day later so 12k is more likely as of now.
Also, "according to indicative estimates of Ukraine’s military, Russia also lost 285 tanks, 985 armored fighting vehicles, 109 artillery pieces, 50 MLRS, 21 anti-aircraft warfare, 44 planes, 48 helicopters, 447 cars, 2 speedboats, 60 fuel tanks, and 4 UAVs."
http://kyivindependent.com/