A person claiming to be from my bank called from a Polish landline and asked me to confirm some information. I ended the call. Would a reverse lookup help check whether the displayed number is genuine?

Ending the call was a sensible precaution when someone unexpectedly asks for banking information. I wouldn’t use a reverse lookup as the only way to prove that the caller was genuine, because even a familiar-looking number isn’t enough evidence by itself. You can still search it on https://scannero.com/who-called-me/poland/ for additional context. For anything involving your bank, however, contact it through the official number on your card, statement, or official website.