That's not enough information.
Ask your friend is he was
Ausgeweisen (Deported) or if he
Abgeschoben (removed). There is a very big difference.
If deported, then according to German immigration law, he has no chance whatsoever of getting back except in humanitarian cases.
If removed, let him find out from the German authorities how long his ban is (should be over by now or latest next year).
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