Every rigid body has 6DOF potential in 3D space.
One point has to be fixed to an x,y,z location – so that holds the first 3 DOF.
The vector from it to any given point in the rigid object has to be constant in the z axis – because the length/distance of the vector doesn’t change in a rigid object, so that leaves x,y (A.k.a, pitch for the x and roll for the y) to be fixed on the end of the vector.
So that’s another 2DOF that are fixed.
And the last 1DOF is the rotation (z, A.k.a yaw) around the now fixed-5DOF vector until it is also fixed to a new fixed 6DOF.