Can Foreign Lawyer be legal consul in German ?
I am from Turkey and want to open an office in Germany.
I research on the internet and read that
Aufenthaltsgesetz "§ 21 Selbständige Tätigkeit" .
But maybe it is not for lawyers.
Anyone do know about it?

That's a visa for self-employed people. The rules are different for foreign lawyers. I know that lawyers from inside the EU can work as a foreign lawyer but can't advise on German law and can't represent in court. I believe that for lawyers from WTO countries, they can consult on issues related to law in their home countries. Check with the German authorities.