https://wpbakery.atlassian.net/wiki/display/VC/How+to+Manage+List+of+Google+Fonts
Remove the list of fonts from
wp-content/plugins/js_composer_theme/include/params/google_fonts
google_fonts.php
Or To change this list use add_filters(‘vc_google_fonts_get_fonts_filter’,’your_custom_function’); and change array
vc_filter: vc_google_fonts_get_fonts_filter