[from the RP site]
Once you've successfully completed the download, you will be ready to install the RealPlayer. To do this, you must make the installer executable and then run it:
chmod u+x rp8_linux_powerpc_cs1.bin
Open a konsole or is it Terminal in redhat...
Make sure your in the directory where you have the RP file.
For example desktop.
So change the directory.
Then type: chmod u+x rp8_linux_powerpc_cs1.bin