As a general rule forces on the offense tend to suffer more casualties than on defense.
If Russian forces attempted an offense it stands to reason their losses are higher.
How high is the question and I doubt we’ll hear a correct estimate from neither side.
In the midst of a hot war there is no reason for any government to tell the truth about their own forces or the enemy’s. Whichever side you are on, it is pointless to take any of these reports seriously.