I imported some assets and, I used some prefabs from that assets. Some of them responds when I add the component of mesh collider to it and disable the ability of going through with it. But some of the is not is not. I can still go through them. Is it a good practice to add 3d cube and disable that or, is there any other way to disable of going through it?
I remember having something like this happen to me as well.
Is it a good practice to add 3d cube and disable that or, is there any other way to disable of going through it?
If it works, it works. But personally, I just manually add a primitive collider (box, sphere, cone etc) for simple meshes and a mesh collider (https://docs.unity3d.com/Manual/class-MeshCollider.html) if I have a complex mesh.
As for the meshes not responding to collision, try checking the static checkbox. If a game object is static, it will not move. See: https://docs.unity3d.com/Manual/StaticObjects.html