Hi,
Use the Grid's OnMouseUp event:
procedure TForm4.gridMouseUp(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
var
ACol, ARow: Integer;
begin
if Button = TMouseButton.mbRight then
begin
grid.MouseToCell(X, Y, ACol, ARow);
ShowMessage('Col: ' + ACol.ToString);
end;
end;
HTH