Thank you, you are right, its working when using repeater or editable text. Actually I am displaying content value in label in my custom web part. So now I have used Resolve dynamic controls API, but still its not working.
<asp:PlaceHolder runat="server" ID="plcContent">
<asp:Label ID="lblContent" runat="server" EnableViewState="false"></asp:Label>
</asp:PlaceHolder>
API
CMS.Base.Web.UI.ControlsHelper.ResolveDynamicControls(this.plcContent);
it's working fine when I used Literal instead Label.