Pivot Points in R6

Recently, I’ve been trying to import avatars in blender with their textures to pose them and render them. I’ve have a lot of trouble with texturing in R15, so someone suggested going to R6. This cleared my issues with texturing, but now when I try to move certain parts of their arms they just won’t move how I want them to. For example: in the images below, I try to rotate the lower limbs of the arm of the avatar through all 3 axis, but once I rotate them, those limbs only rotate along one axis. Is there any way to fix this?

If you have any suggestions to circumvent this problem, I’m all ears!

I don’t think you can rotate the lower limbs of the arm of an R6 character because the arm is just one mesh.