Identify what kind of BIN file it is
Try opening it with the program that created it
Use a disc image tool if it is a CD/DVD BIN file
Mount it with a virtual drive application
Convert it to ISO if needed
Open it with a hex editor if it is a raw binary file
Use a text editor only if you know it contains readable text
Rename the file extension only if you are sure of the correct format
Scan the file for malware before opening unknown BIN files