What TOEFL score do you need for Ruhr University Bochum?

Lasers and Photonics says it accepts only the listed certificates and that medium of instruction certificates are not accepted. A language certificate must be uploaded while the application portal is open; a missing certificate, or one with too low a score, makes the application incomplete and it is excluded. Electrical Engineering and Information Technology requires B2 at the time of enrolment.

For comparison, the Lasers and Photonics page asks for IELTS Academic 6.0, and the Computational Engineering page asks for 6.0 with 6.0 in all four parts.

The pages do not describe a conditional English route. Computational Engineering accepts confirmation from your university that your first degree was completed entirely in English, and Lasers and Photonics may consider the Oxford Test of English (120) or PTE Academic (55) as equivalent.

Requirements vary by programme and change between admissions cycles. The score that binds you is the one on your Ruhr University Bochum programme page and in your offer letter, so check it there before you book a test.