Tiles in a RadTileList controls can be selected by using the right mouse button or by holding down the tile and dragging it a little downward or upward, like in Windows 8.
A selected tile shows an indicator in its top-right corner.
The SelectionMode property controls this behavior - depending on its value selection can be disabled, many items can be selected at once, or only a single item can be selected. The type of the property is Telerik.Web.UI.TileListSelectionMode, both on the server and on the client, and the possible values in the enum are None, Single, Multiple.
Like in Windows 8, use the right mouse button to select a tile or hold down the tile and drag it a little downward or upward. A selected tile shows an indicator in its top right corner.
When a product is selected it will be added to the basket with the data obtained from the tile list.
By default, the TileList performs selection on the client, and you can have it postback on each selection by toggling the "AutoPostBack on selection" checkbox.
Disabling or enabling automatic postbacks clears the basket, so you can use the client-side or server-side API of the control to perform the same task.
Use the RadioButton Lists to choose the selection mode of the control.