As an osteopathic student, if you apply for ACGME residency and have taken the USMLE (whether or not you passed), you are required to report that you have taken the USMLE. You can not hide the fact you took the exam. You do not have the option to release either step 1 or step 2- you can only release your scores. All of them as they stand on your record.
However, if you apply AOA only, you do not have to release your USMLE scores.
If you have taken the USMLEs and do not report your scores and enter the ACGME match, you risk being found guilty of a match violation and your match could be null and void and you can be blacklisted from future match participation.