get url id of the home controller?

public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
        }

public class HomeController : Controller
   {
       public ActionResult Index(int? id = null)
       {
           ViewBag.ID = id;
           return View();
       }

   }

public class FacilityAddController : Controller
    {
 public ActionResult GetID()
        {

           var id= Request.RequestContext.RouteData.Values["id"];

            return Json(id, JsonRequestBehavior .AllowGet);
        }

}