Under the Fair Credit Reporting Act, if you submit an application for credit and then are denied that credit, the person who access that information is required to submit to you an adverse action letter. This letter should identify who provided information regarding your credit and what information they used to deny you the credit.
You should keep in mind that applications for rental can be denied for many more reasons than just credit alone. Common tenant screening can include consideration of your employment, income, rental history, criminal record, pets, and more. Pretty much anything that isn't prohibited in Federal, State and Local fair housing laws can be used to determine your eligability for rental.
It's tough out there for renters right now - good luck!