Odata Dev

Hi, I open ProGuard UI and Added input jar and on the final stage i clicked Process! button. Process is completely successfully. Where i see the converted, obfuscated jar file? location of the obfuscated jar file? 2nd question, can i obfuscate the application jar files alone instead of obfuscating rt.jar java file as well? I have one jar and need to obfuscate it and struggling with the steps. I am using MAC OS. Please kindly advise. Thanks.