Make an Object avoid another

 var hit : RaycastHit;
 var forward  = transform.TransformDirection(Vector3.forward);
 if(Physics.Raycast(transform.position,forward,hit, 5)){
    if(hit.collider.tag == "objecttag"){
       transform.Rotate(Vector3.up * 10);
 }}

What that does is point a raycast in front of your AI. If the ray hits the tag of your objecta/objectb it'll rotate the object to avoid the other object. All you have to do to this code is change the "objecttag" to the tag of your object. Enjoy!