CSHARP

unity check when clicked on object

 
void Update()
{
  // Check for mouse input
  if (Input.GetMouseButton(0))
  {
  	Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
   	RaycastHit hit;
   	// Casts the ray and get the first game object hit
   	Physics.Raycast(ray, out hit);
   	Debug.Log("This hit at " + hit.point );
  }
}

unity detect when an object has been clicked

public class MyObject : MonoBehaviour, IPointerDownHandler
{
    private void Start()
    {
        AddPhysics2DRaycaster();
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        Debug.Log("Clicked: " + eventData.pointerCurrentRaycast.gameObject.name);
    }

    private void AddPhysics2DRaycaster()
    {
        Physics2DRaycaster physicsRaycaster = FindObjectOfType<Physics2DRaycaster>();
        if (physicsRaycaster == null)
        {
            Camera.main.gameObject.AddComponent<Physics2DRaycaster>();
        }
    }
}