Hello Sangeetha,

Could you please take a look if the following code sample suits your needs:

private void ultraGrid1_InitializeGroupByRow(object sender, Infragistics.Win.UltraWinGrid.InitializeGroupByRowEventArgs e)
{
   e.Row.Band.Summaries[0].DisplayFormat = "{0}";
   e.Row.Band.SummaryFooterCaption = "Sum = ";
}

If this is not what you are after, please provide a screenshot of your requirements.