I have found solution for above question after researching telerik mvc documentation
Reason for the above problem is, Ajax returned html contents is not getting reference of registered java scripts. So on success of ajax call we need manually register needed telerik scripts to access telerik mvc controls as like below"
var telerikScriptArray = new Array();
telerikScriptArray[0] = "/Content/Scripts/Telerik/jquery-1.7.1.min.js";
telerikScriptArray[1] = "/Content/Scripts/Telerik/telerik.common.min.js";
telerikScriptArray[2] = "/Content/Scripts/Telerik/telerik.calendar.min.js";
telerikScriptArray[3] = "/Content/Scripts/Telerik/telerik.datepicker.min.js";
telerikScriptArray[4] = "/Content/Scripts/Telerik/telerik.timepicker.min.js";
telerikScriptArray[5] = "/Content/Scripts/Telerik/telerik.combobox.min.js";
$.ajax({
type: "POST",
url: $Url.resolve("~/Ares/Controller/Action"),
data: { AccountId: accountId},
sucess:function(data){
$.telerik.load(telerikScriptArray, function () {
$("#controlID").data("tDatePicker").disable(); // Here you can access ajax returned telerik controls.
});
},
error:function(){
}
});