Hi Mahesh,
There will be one event in Ajax tab container called onactivetabchanged, use this event and write the code for each tab panel when the activetabindex was changed. And make sure you've set AutoPostback=true. Find the below sample code FYR,
<asp:tabcontainer id="tbhead" runat="server" xmlns:asp="#unknown">
ActiveTabIndex="0" AutoPostBack="true"
Width="100%" Height="100%" onactivetabchanged="tbhead_ActiveTabChanged">
<asp:tabpanel id="tab1" runat="server" headertext="sample">
</asp:tabpanel></asp:tabcontainer>
In .CS file,
protected void tbhead_ActiveTabChanged(object sender, EventArgs e)
{
if (tbhead.ActiveTabIndex == 0)
{
}
else if(tbselfappr.ActiveTabIndex == 1)
{
}
}