[AlexSku]

Код:

procedure TForm1.DrawGrid1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  ACol, ARow: Integer;
begin
  DrawGrid1.MouseToCell(X, Y, ACol, ARow);
  ShowMessage(Format('Col %u, Row %u', [ACol, ARow]));
end;