Welcome to the Wefugees community and thank you for your question.
May I ask which High Court is processing your case? Sometimes they give information about the estimated time they need on their website.
In general, you have to be patient because German bureaucracy is not the fastest. Especially courts usually have a high workload. Did you contact them and ask them about any progress on your case? If you do so, you probably should mention your "Aktenzeichen" (file number or reference numer) so that they know what you are talking about.