Modify the result data before passing to DropDownList when binding remote data source

<div class="control-wrapper">
    <div id="default" style='padding-top:75px;'>
        <ejs-dropdownlist id="customers" actionComplete="actionComplete" query="new ej.data.Query().from('Customers').select(['ContactName', 'CustomerID']).take(6)" placeholder="Select a customer" popupHeight="200px">
            <e-dropdownlist-fields text="ContactName" value="CustomerID"></e-dropdownlist-fields>
            <e-data-manager url="https://services.odata.org/V4/Northwind/Northwind.svc/" adaptor="ODataV4Adaptor" crossDomain="true"></e-data-manager>
        </ejs-dropdownlist>
    </div>
</div>
<script>
    function actionComplete(e) {
        // initially result contains 6 items
        console.log("Before modified the result: " + e.result.length);
        // remove first 2 items from result.
        e.result.splice(0, 2);
        // now displays the result count is 4.
        console.log("After modified the result: " + e.result.length);
    }
</script>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using WebApplication1.Models;

namespace WebApplication1.Controllers
{
    public class DropDownListController : Controller
    {
        public ActionResult modifydata()
        {
            return View();
        }
    }
}