I have used rad date picker in one of our web page.It is rendering perfectly.
but when set the compatablility setting of IE11. total control display is changed.
<telerik:RadDatePicker RenderMode="Lightweight" ID="rdFrmInspDate" Width="135px" runat="server" Height="20px" DateInput-Label=" " MinDate="" Skin="Web20"></telerik:RadDatePicker>
Please find screen shot for reference