What are the rules which I have to respect to make the Form scrollable...
I simple set the Property AutoScroll to true.
I also tried while Auto Sc
The AutoScroll property should work fine, but most likely you are not using it right: the bar appears only when required. Example: minimum Y of the Form is 0 and minimum Y of one of the controls in it (a TextBox) is -20.
If you want to include a scroll bar no matter what (controls inside the boundaries of the form or not), you can also do it. Sample code (from MSDN) for a vertical scroll bar:
// Create and initialize a VScrollBar.
VScrollBar vScrollBar1 = new VScrollBar();
// Dock the scroll bar to the right side of the form.
vScrollBar1.Dock = DockStyle.Right;
// Add the scroll bar to the form.
Controls.Add(vScrollBar1);