<meta http-equiv="refresh" content="600">
If you want to add this from code behing, then you can add it like this:-
protected void Page_Load(object sender, EventArgs e)
{
HtmlMeta hmRefresh = new HtmlMeta();
hmRefresh.HttpEquiv = "Refresh";
hmRefresh.Content = "10";//Time in seconds
Page.Header.Controls.Add(hmRefresh);
}