Thank you for being such an active member of the Wefugees community!
Could you please clarify your situation for me - the mother of your child has sole custody? You two are not married, is that correct? I'm not sure I understand what you mean by "surkarest" - are you referring to custody (Sorgerecht)?
If you are asking what your chances are to receive a residence permit as the father of a child that you don't have custody of, the answer on this thread might help: https://***.wefugees.de/800048/residence-permit-germany-because-mother-residence-permit
As the experts mentioned on the thread,
"As a father of an underage child who does not have the German citizenship, you can try to apply for a residence permit, but you´re not entitled to get it granted."
It looks like the best thing you can do is to talk to a lawyer (or seek free legal advice). Here is a website listing places where you can receive free legal advice in Germany: ****://***.refugeelegalaidinformation.org/germany-pro-bono-directory
If these sources don't answer your question, please get back to me with the information I asked you for and I will do some more research.
All the best,