Learn how to select objects in the Render Window in VRED.
Video captions: The Shift button on your keyboard is the button you need to press, in order to interact with objects in your viewport. Activate Wireframe in your toolbar to receive feedback from your selection in the viewport.
To select a geometry in VRED, just hold Shift and left-click on it.
To select multiple objects, use Ctrl + Shift + left-click.
To deselect objects from your selection, use Ctrl + Shift + right-click.
To deselect all objects, simply Shift + right-click anywhere in the viewport.
You can also select objects by framing them. Draw a frame from the upper left to the bottom right, while Shift + left-clicking. All objects within the frame will be selected.
But, if you draw a frame from the lower right to the upper left, objects which are connected to the selected frame in the background will also be selected.