Exclude TEC Categories

/**
 * If you want to manually exclude certain categories and
 * don't wish to use the pre_get_posts hook for instance
 * (example here: http://pastebin.com/91cpt8mh) then this
 * would be another approach.
 */
if (tribe_event_in_category('slug-to-exclude') === false) {
    /* Code to display the event */
}