find vector3

             float range = 3f;
             Vector3 Tp = target.transform.position;
             Vector3 Pp = player.transform.position;
 
             // vector from target to player
             Vector3 targetToPlayer = Pp - Tp;
             // vector with same direction as "targetToPlayer", but length of "range"
             Vector3 targetToPlayerWithRangeLength = targetToPlayer.normalized * range;
 
             // start from target and come towards player the "range amount".
             Vector3 positionOfSpot = Tp + targetToPlayerWithRangeLength;

First, you need to get the vector3 of the orientation towards the target. After that, you will need to get only the part up to the circle around the target.

To get the orientation, simply substract them from one another :

 Vector3 orientation = (target.position - player.position);

Afterwards, substract the value of the range from it, like so :

 //Get the orientation of previously found vector
 Vector3 GreenVector = orientation.normalized;
 
 //Get the lenght of the previous vector minus the range
 GreenVector = GreenVector * (orientation.magnitude - range); 

That should get you the green vector on the picture.

EDIT: Now, if you want the position of the point, simply add the player's position to GreenVector.

 Vector3 DesiredPosition = PlayerPosition + GreenVector;

             if(hit.collider.gameObject.tag == "Tower"){
                 Transform tower = hit.collider.gameObject.transform;

                     Vector3 Tp = tower.position;
                     Vector3 Pp = this.gameObject.transform.position;
                     
                     Vector3 targetToPlayer = Pp - Tp;
                     Vector3 targetToPlayerWithRangeLength = targetToPlayer.normalized * rangeShoot;
                     
                     Vector3 positionOfSpot = Tp + targetToPlayerWithRangeLength;
                     target.position = positionOfSpot;

                     Instantiate(marker, positionOfSpot, Quaternion.identity);
                 }}

hi All, thanks for responses, working perfect :)

terimakasih (bahasa)