Hi! I wanted to ask if it is possible to set all(or part of) normals of an object facing upwards even if face is facing left or right! Maybe there is a way to do it?
if the floor underneath it is facing upwards you could have it align itself to floor normals.
You should define upwards; do you mean the world Z axis, or the normal of the surface?
For the former, you can get a script to set the normal to (0, 0, 1), whilst the latter requires a ray-cast to find the normal of the surface.
By the way, you don’t need to end all of your titles with an exclamation mark, i’m sure we all know it’s important to whoever posts it 
Normals are vectors perpendicular to the surface of each polygon:
Those blue lines are normals.
There’s no way to change that data with logic bricks, or even with python: You could manipulate the mesh with python, which may recalculate the normal data, but, as far as I know, you can’t set normals directly.
You can modify the normals of the object with the KX_VertexProxy interface in Python (normal attribute). You can also, since 2.74, modify the normals with a modifier. It is not currently, nor likely to be, exposed to the logic bricks
Oh, right, it has a normal attribute.