Animations reference the root skeleton, so for an animation to work on another character's skeleton, the points must be the same. If they are not the same, you need to retarget the animations. This requires an animator, it's not easy. Another method is to use an Animation tool asset using Unity 3D and re-export the animations and root motions, then if you have a suitable exporter you can extract them in gr2 format with 3dsmax. Of course, it is important to remember that this Unity3d tool has I.K support, so you need to format Axis accordingly. That's all.
