Hi, RAR compression requires a license. If you have the licensed library, I certainly can do this for you. Decompressing RAR files, however, can be done without license. If you don´t have a licensed library for RAR compression, we could use one of many other free, open source libraries available and use a different compression format (i.e.. pkZip, etc).Since you need your application to run on OS X, we may have limitations in the number of open source libraries we can choose from. I have more than 30 years programming in Delphi (since it started as Turbo-Pascal!)
If you are interested, please let me know.
Kind regards,
Marco García