The German as a Foreign Language Office does not offer any official German examinations. If you want to take a recognized diploma in German, there are various opportunities open to you in the Bern area.
Two large service providers
Some examinations are virtually identical, with others there are major differences. The Goethe-Institute is older and more well known than TELC which is not a reflection on the quality of TELC. TELC seems to be more vocationally oriented than the Goethe Institute, which also covers cultural and political aspects of education at a high level.