Note that depending on RadDropDownList location on the screen, its popup will be opened on a way to display entirely. Hence, its location(left, right, top, bottom) may vary. However, you can specify where to position the popup by canceling the PopupOpening event and manually showing it at the desired position. You can find below a sample code including the desired formatting from the attached screenshot:
I hope this information helps. Should you have further questions, I would be glad to help.
Regards,
Dess
Telerik
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