To set a specific CSS class for a column in your table, you can use the following code snippet. First, you need to access the TableDescriptor to get the column and then apply the desired CSS class.
this.GridGroupingControl1.TableDescriptor.Columns[2].Appearance.AnyRecordFieldCell.CssClass = "MyColumnClass";
If you want to apply CSS styles to a specific cell within a column, you can use the code below:
if (((Syncfusion.Web.UI.WebControls.Grid.Grouping.GridCell)(e.Row.Cells[i])).ColumnDescriptor.Name == "ShipCity")
{
e.Row.Cells[2].CssClass = "MyCellClass";
}