boxGO.parent = Hit.transform;

boxGO.transform.parent = Hit.transform;

using UnityEngine;
using System.Collections;

public class Gravi : MonoBehaviour {
public Transform camera1;
private RaycastHit Hit;
public float Dist = 1;
public Rigidbody cube;
public Color c1 = Color.red;
public Color c2 = Color.white;
Vector3 firePoint;  
Vector3 hitPoint;  
private Rect crossHairPosition;  
public Texture2D crossHairTexture;  
//
void Start () {  
renderer.material.color = Color.red;
}
//  
void Update () {   
if(Input.GetKey(KeyCode.Mouse0)){
Dist = Vector3.Distance(Hit.point,transform.position);    
Vector3 Direction = camera1.TransformDirection(Vector3.forward);;    
if(Physics.Raycast(camera1.position, Direction, out Hit,10000f)){
Hit.transform.rigidbody.AddForceAtPosition(Direction*200,Hit.point);  
cube.transform.parent = null;        
}
}
if(Input.GetKey(KeyCode.Mouse2)){
Dist = Vector3.Distance(Hit.point,transform.position);     
Vector3 Direction = camera1.TransformDirection(Vector3.forward);;    
if(Physics.Raycast(camera1.position, Direction, out Hit,10000f)){
Hit.transform.rigidbody.AddForceAtPosition(-Direction*20,Hit.point);
if(Dist <=10){
GameObject.FindWithTag("Cube").transform.parent = transform;        
Hit.transform.rigidbody.Sleep();  
Hit.transform.rigidbody.useGravity = false;     
}else{      
Hit.transform.rigidbody.useGravity = true;
}
}
}
}
void OnGUI(){  
GUI.DrawTexture(crossHairPosition, crossHairTexture);    
}
}