If an aircraft have two vertical tails then pilot push in the rudder pedal the rudders will not be deployed at the same angle.It is used throughout the all envelope of flight or is it possible only for low speed? Why and which ones is more deflected?
The jet in the top picture is turning slightly left using nose wheel steering, which is generally the same control as the rudder. I'm not aware of any fighter jet that has a tiller. Therefore the computer has commanded the rudders to deflect left. This is likely combined with a "toe in" (a characteristic of some fighters that aids in stability) of the rudders so it looks like only one has moved.
In the bottom picture, the flight control computer has decided that the best way to maintain the pilot's commanded attitude is to asymmetrically deflect the rudder. Flight control computers move surfaces in fly-by-wire systems, not pilots. Pilots just ask the computer if it is okay to do that. The computer decides if it is okay and how. It will use a combo of all the available surfaces to achieve the desired attitude within the programmed flight envelope and it doesn't have to do it symmetrically.