Hello Rajesh Aggarwal,
Please check
this help article which demonstrates how to ajaxify controls with RadAjaxManager. Here is a sample declaration which shows how to ajaxify RadTreeView and RadGrid:
<telerik:RadAjaxManager runat="server" ID="RadAjaxMAnager1">
<AjaxSettings>
<telerik:AjaxSetting AjaxControlID="RadTreeView1">
<UpdatedControls>
<telerik:AjaxUpdatedControl ControlID="RadGrid1" />
<telerik:AjaxUpdatedControl ControlID="RadTreeView1" />
</UpdatedControls>
</telerik:AjaxSetting>
<telerik:AjaxSetting AjaxControlID="RadGrid1">
<UpdatedControls>
<telerik:AjaxUpdatedControl ControlID="RadGrid1" />
<telerik:AjaxUpdatedControl ControlID="RadTreeView1" />
</UpdatedControls>
</telerik:AjaxSetting>
</AjaxSettings>
</telerik:RadAjaxManager>
Greetings,
Albert
the Telerik team