If the theme described that WPBakery plugin included in the theme then I am sure to get that plugin and amy be some other plugins you will get when you will install theme then the theme will recommend for necessary plugins to install. You have to follow the recommendation plugins and you will be able to install the plugin from the author resources repository. But most cases customer have to activate theme license to get those recommend plugins.
So, please check theme documentation. I hope you will get all necessary guideline how to install theme, plugins and all other things.