Using PartialView in Layout page in ASP.Net MVC

hello,

i have partial view like this, current the partial viw is in index page so its working, but when i move this partial layout from index page to shared layout(hdeader) so below partial only works on index page and on other pages it is not working

currently i am calling data method on index controller where should i move the data method so partial view can call the method on all pages what ist he global place to pass it

please advice

@using System.Data
@model DataTable

@foreach (DataRow row in Model.Rows)
{
    <li class="dropdown megamenu-fw">
        <a>@row["gender"]</a>
        <ul class="dropdown-menu fullwidth" style="display: none;">
            <li class="megamenu-content">
                <div class="mega-content">
                    <div class="mega__item">
                        <h6><a>Second CAtegory</a>
                        </h6>
                        <small>
                            <ul>
                                <li><a># level</a></li>
                            </ul>
                        </small>
                    </div>
                </div>
            </li>
        </ul>
    </li>
}

Controller

        public ActionResult Index()
        {
            DataTable ds = new DataTable();
            CategoriesBL fc = new CategoriesBL();
            ds = fc.SelectFirstCategoriesBL();
            //Fille properties of contractIdetails
            return View(ds);
        }