Not sure what a BAI file is myself. But if you just need to rename it, you can do this with BizTalk. Not the best though due to all the message box storage. If you just wanted to rename it, you could set up a Receive Port & Location with a Custom Made Pipeline and a Send Port filtering on it, also with a PassThrough Pipeline. Inside the custom pipeline, you’ll need to look at the File.ReceivedFileName property and change it as needed. Then use the %SourceFileName% macro to name the file.
If you need to convert the data, BizTalk is a better fit. You would want to do that inside the Custom Receive Pipeline. The file naming steps would still be the same.