Rigidbody.velocity Not working on parent rigidbody with four child rigidbodies attached to it

As the question states, I am trying to move a rigidbody 2d (an empty gameobject) that is holding four 2d gameobjects with rigidbody attahed to them. I am trying the move the parent rigidbody object using the rb.velocity but it is not moving the gameobject however the position values in the inspector are changin. When I am trying to move the parent gameobject after removing the c$$anonymous$$ld gameobjects, it is working and the same is working for the c$$anonymous$$ld gameobjects too.. What possibly could be the issue. In the unity documentation(https://docs.unity3d.com/Manual/class-Rigidbody.html) it is clearly mentioned that a parent object will move alongwith the c$$anonymous$$ld gameobjects.