This is one of the most asked, least answered questions from people considering Ausbildung from abroad. The law actually covers it — most informal advice just doesn’t mention that it does.
§16a AufenthG — the same law that grants your training residence permit — includes a specific provision for exactly this situation. If your permit is withdrawn or shortened through no fault of your own — your company closes, goes bankrupt, or otherwise can no longer train you — you get up to six months to find a new training place before your residence status is actually at risk. That’s written into the statute, not left to an immigration officer’s discretion.
During that window, you’re in the same position as someone searching for a first training place: looking for a company, interviewing, arranging a new Berufsausbildungsvertrag. If you find one and it’s registered with the relevant IHK or HWK within that period, your training continues on broadly the same terms.
The six-month window is for when the company itself fails or can no longer train you — not for a voluntary decision to quit, or for serious misconduct on your part that ends the contract. Those situations are handled case by case and are genuinely worth a consultation with an immigration lawyer or your local Ausländerbehörde rather than relying on a general guide.