We do not guarantee trademarks on any of the names submitted in our contests, since in order to file a trademark we would need to know how the name is being used in business (what industry, the specifics of what the company or product is selling/doing, etc.).
We recommend seeking legal advice to ensure that your preferred name suggestion does not have an existing trademark within your business sector. Keep in mind that if there is an existing trademark, as long as your business is in a different industry you would be able to file a trademark too -- for example a cosmetic company could trademark the name "Apple", since it does not conflict with the computing company.