Mvc de View den Conroller a veri yollarken veri null gidiyor

<script type="text/javascript">

    var ililce;
    var hizmet;

    function ara() {

        ililce = $("#ililce").val();

        hizmet = $("#hizmet").val();

        $.ajax({

            type: "POST",

            url: "/Home/Arama",

            data: { a: ililce, b: hizmet },

        });

    }


</script>

@using (Html.BeginForm())
{
    <div class="col-md-12">
        <div class="card border-dark md-12">
            <h5 class="card-header">Randevu Bul</h5>
            <div class="card-body">
                <div class="row">

                    <div class="form-group col-md-4">
                        <label>Sehir & İlçe Seçimi</label>
                        <select class="form-control" id="ililce">
                            <option selected value="0"></option>
                            @foreach (var item in Model.ilListNesnesi)
                            {
                                <option disabled style="font-size:20px;">@item.ilAdi</option>
                                foreach (var itemm in Model.ilceListNesnesi)
                                {
                                    if (item.ilId == itemm.ilId)
                                    {
                                        <option style="font-size:15px;" value="@itemm.ilceId">  @itemm.ilceAdi</option>

                                    }
                                }
                            }


                        </select>
                    </div>

                    <div class="form-group col-md-4">
                        <label>Hizmet</label>
                        <select class="form-control" id="hizmet">
                            <option selected value="0"></option>
                            @foreach (var item in Model.HizmetKategoriNesnesi)
                            {

                                <option disabled style="font-size:20px;">@item.KategoriAdi</option>
                                foreach (var itemm in Model.HizmetlerNesnesi)
                                {
                                    if (item.HizmetKategoriId == itemm.HizmetKategoriId)
                                    {
                                        <option style="font-size:15px;" value="@itemm.HizmetlerId"> @itemm.HizmetAdi</option>
                                    }
                                }


                            }


                        </select>
                    </div>
                    <div class="col-md-4">
                        <h4>Aranacak Salon Adı</h4>
                        <input class="col-md-12" type="text" id="isletmeadi" />
                    </div>
                    <hr />
                    <button type="submit" class="btn btn-lg col-md-4 offset-4 btn-success" onclick="ara()">Randevu Ara</button>
                </div>
            </div>
        </div>
    </div>

}

    [HttpPost]
        public ActionResult Arama(string a,string b)
        {
            int c = int.Parse(a);
            int d = int.Parse(b);


            return RedirectToAction("AramaHata");
        }