Starting from version 4.3 Visual Composer allows you to control columns across multiple devices. Responsive settings can be found in column param window under tab 'Width & Responsiveness'.
Within settings it is possible to set column width and offset for default column size and also other devices by taking into account default value. In addition it is possible to 'Hide' columns on specific type of devices in order not to display some specific block for example on mobile devices.
Note: Starting from version 4.7 is is possible to use Responsive Settings for inner column