You can do this handling QueryCellStyleInfo. In the handler, explicitly set e.Style.ReadOnly = true based on whatever criteria you need. This code sets a row readonly is the AAs field value is AAA4.
private void gridGroupingControl1_QueryCellStyleInfo(object sender, GridTableCellStyleInfoEventArgs e)
{
if(e.TableCellIdentity.TableCellType == GridTableCellType.RecordFieldCell
|| e.TableCellIdentity.TableCellType == GridTableCellType.AlternateRecordFieldCell)
{
GridTableDescriptor td = this.gridGroupingControl1.TableDescriptor;
GridRecordRow rec = e.TableCellIdentity.DisplayElement as GridRecordRow;
if(rec != null)
{
DataRowView drv = rec.GetData() as DataRowView;
if(drv != null && drv["AAs"].ToString() == "AA4")
{
e.Style.ReadOnly = true;
}
}
}
}