Dropdown With Ajax

 Dropdown Method

public ActionResult Index()
        {
            List<TblCountry> countries = _db.TblCountries.ToList();
            List<TblDepartment> departments = _db.TblDepartments.ToList();
            ViewBag.ConList = new SelectList(countries, "Country_Id", "Country_Name");
            ViewBag.DepList = new SelectList(departments, "D_Id", "D_Name");
            return View();
        }

 Multiple table show data list with viewmodel 

 public ActionResult ViewAll()

        {

            _db.Configuration.ProxyCreationEnabled = false;

            List<VmClass> vm = _db.TblUsers.Select(x => new VmClass

            {

                User_Id = x.User_Id,

                User_Name = x.User_Name,

                User_Gender = x.User_Gender,

                Country_Name = x.TblCountry.Country_Name,

                D_Name = x.TblDepartment.D_Name,

            }).ToList();

            return Json(new { data = vm, status = "success" }, JsonRequestBehavior.AllowGet);

        }

 Dropdown On View 

@Html.DropDownListFor(model => model.D_Id, ViewBag.DepList as SelectList, "Select Deppatment", new { @class = "form-control" })

Append data with Ajax and show List

function LoadData() {

    $.ajax({

        url: "/Home/ViewAll",

        type: "Get",

        dataType: "json",

        success: function (result) {

            $("#List").empty();

            if ($("#List").empty()) {

                $.each(result.data, function (key, value) {

                    var html =

                        "<tr>" +

                        "<td>" + value.User_Name + "</td>" +

                        "<td>" + value.User_Gender + "</td>" +

                        "<td>" + value.Country_Name + "</td>" +

                        "<td>" + value.D_Name + "</td>" +

                        "<td>" + '  <a href="#" class="btn btn-success" onclick="Edit(' + value.User_Id + ')">Edit</a>' + '  <a href="#" class="btn btn-danger" onclick="Delete(' + value.User_Id + ')">Delete</a>' + "</td>" +

                        "</tr>"

                    $("#List").append(html)

                })

            }

        },

        error: function () {

             alert("error");

        }

    });

}