Hi Rashmikant patel,
you can use DisplayAfter property of UpdateProgress like as shown below in code its value will be in Miliseconds
<asp:updateprogress id="UpdateProgressbar" runat="server" enableviewstate="false" displayafter="5000" xmlns:asp="#unknown">
<progresstemplate>
<div id="dvBg" style="display:block; width:100%; background-color:#2F8AFF; height:200%; text-align: center;opacity:0.6;position: absolute; left: 0px; top: 0px; ">
<div id="tblLoading" style=" width: 300px; height: 50px;margin-top:25%;marginleft:42%;">
<img src="Image/progress_bar.gif" alt="Please wait..." />
</div>
</div>
</progresstemplate>
</asp:updateprogress>
here 5000= 5 seconds
Hope this works!!!!
If yes, do not forget to mark as answer