this plugin comes with your theme. So – for updating – I need a zip of the latest version from you.
I found the following text on the plugin site (https://wpbakery.atlassian.net/wiki/pages/viewpage.action?pageId=524337): How to update and receive support if I do not purchase direct license?
In such case you need to wait on your WordPress theme author to update Visual Composer on their side and push it to you. Also support related questions should be addressed to your WordPress theme provider.