Hi Sabu,
You can remove the rows in a GridControl by using the GridControl.Rows.RemoveRange method. And insert rows into a GridControl by using the GridControl.Rows.InsertRange method. Below is a forum thread that discuss with the multiline textbox in a cell.
http://www.syncfusion.com/support/Forums/message.aspx?&MessageID=56831Best regards,
Haneef