I'm using contractubex gel for removing my burn scars but now I feel itching and dry hard skin. Is it normal or not?

It is impossible to fully answer your question without being able to see the scar.  I recommend an in-person evaluation with a board-certified dermatologist to fully assess the area of concern.  
As a general principle, there are many possible treatments for scars, including topical medicines, lasers, and surgical revision, among others.  Among topical treatments, the only option with good evidence in my opinion is silicone gel, and I recommend silicone gel or silicone gel sheets to all of my patients who are concerned about scars.  Regardless, it's best to see a board-certified dermatologist in person for an assessment and to discuss all of your options.