JointContain.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class JointContain : MonoBehaviour
{
    [SerializeField] private List<Transform> joints = new List<Transform>();
    [SerializeField] private Transform ballCenter;
    [SerializeField] private float maxDistanceFromCenter = 1f;

    private void Update()
    {
        foreach (Transform joint in joints)
        {
            Vector3 distance = joint.position - ballCenter.position;
            if (distance.magnitude > maxDistanceFromCenter)
            {
                joint.position = ballCenter.position + (distance.normalized * maxDistanceFromCenter);
            }
        }
    }

    private void OnDrawGizmosSelected()
    {
        Gizmos.DrawWireSphere(ballCenter.position, maxDistanceFromCenter);
    }
}