How to Add Vlaidation in appended(More than one) dropdown list using javascript

<div class="side-by-side fld-wdth-04 mrg-10">
        <span class="field-01-right">
            <select name="@ViewBag.Count" class="chzn-select-deselect dropdept">
                <option value="">Select Institutes</option>

                @foreach (var item in Model.Institutes)
                {
                   <option value="@item.Value">@item.Text>/option>
                    
                }
          </select>
        </span>
    </div>