What is the name of a movie in which a family with a small kid go to a hotel of a friend of theirs and the kid starts seeing weird thing in tat hotel and he must turn around and count to 10 to make those things go back to normal state? There is also a forbidden room in that hotel and when the kid enters it he finds a creepy girn in the bathtub behind the curtain...

Stephen King's The Shining?

No its not the shining for sure. I don't remember any popular actors participating in the specific movie .

I think JudyKayTee is correct - try this scene from The Shining Mini series from 1997. The boy is in the bathroom, counts quickly to 10, reveals a nasty creepy lady behind the curtain...
shining 1997 bathtud scene - YouTube

I've seen the movie a couple of times and the "counting to 10" part is also in the novel.

Well apparently you were right! That's the movie I was searching for. I thought he was referring to the 1980 movie the shining with jack nicholson. Thank you people :)