After your company's subscription is canceled, all existing job postings will continue to run until they expire (after 60 days of being published), or are taken down by one of your company admins.

Under the free plan, your company is only allowed to have 1 job posting at any time. If your company still has more than 1 job posting published after your Premium plan has expired, you won't be able to post any more jobs until you unpublish some of your job postings, or upgrade to TIA Jobs Premium again.