Trying to Disable Compenent when there's a collsion

Well first off in this snippet it does not seem as if you are even defining Controller. Based on the information we have so far here you are. This obviously will only work if attached to the parent of the component you're trying to reach.

 private var Controller : PlayerControls;
 
 function Start()
 {
     Controller = GetComponent(PlayerControls);
 }
 
 function OnCollisionEnter2D (collider : Collider)
 {
     if(collider.gameObject.tag == "GoalFieldR")
     {
         Controller.enabled = false;
     }
 }

As far as I'm aware you can't just use "enabled" variable if you haven't defined one in your script. I encourage you to define one.

Your PlayerControls script :

 public var permission : boolean;
 
 private var screenPoint: Vector3;
 private var offset: Vector3;
 private var curScreenPoint : Vector3;
 private var curPosition : Vector3;
  
 function Start () {
     permission= true;
 }
  
 function Update () {
 }
  
 function OnMouseDown () {
     if(permission)
     {
        screenPoint = Camera.main.WorldToScreenPoint(gameObject.transform.position);
        offset = gameObject.transform.position - Camera.main.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPoint.z));
        Screen.showCursor = false;
     }
 }
  
 function OnMouseDrag() {
     if(permission)
     { 
        curScreenPoint = new Vector3(Input.mousePosition.x, Input.mousePosition.y, screenPoint.z);
        curPosition = Camera.main.ScreenToWorldPoint(curScreenPoint) + offset;
        transform.position = curPosition;
     }
 }
  
 function OnMouseUp(){
     Screen.showCursor = true;
 }

Then you can access "permission" variable like this :

 private var Controller : PlayerControls;
 
 function OnCollisionEnter2D (collider : Collider) {
  
      if (collider.gameObject.tag == "GoalFieldR") {
           Controller.GetComponent<PlayerControls>().permission = false;
      }
 }