Hello and thank you for contacting us. This is Dwayne B. and I’m an expert here and looking forward to helping you today.
First, you need to get a bankruptcy lawyer to get permission from the bankruptcy court for you to file suit in regular court. The judge should do that if you weren't aware he was in bankruptcy at the time he made the rental.
Then, once the judge agrees to "lift the stay" and allow you to proceed in the courts you can sue them in whichever court you prefer so long as you don't exceed the minimum jurisdictional limits. In other words, you can sue in small claims court for an amount up to $10,000, if you are an individual or a sole proprietor. Corporations and other entities are limited to $5,000. If the amount is higher than that then you would have to sue in a higher court and would likely need a lawyer. You would definitely have to have a lawyer if you are not suing in small claims court and you have a corporation.
You can also report the issue to the District Attorney although it's been my experience that they don't get involved, usually, if there is a bankruptcy.
If your question has been answered then I'd offer my best wishes to you and ask that you please not forget to leave a Positive Rating so I receive credit for my work. Of course, please feel free to ask any follow up questions in this thread. I want to be sure that all of your questions are answered.