if your Work visa is ready, RP process (Medical/Fingerprint/stamping RP in your passport/ID card)shouldn't take more than 10 business days. But it depends on your PRO. Some PROs (lazy, stupid, irresponsible, and other halli-walli staff) manage to let you "enjoying" the process for a month and even more.. but it has nothing to do with the process itself..
If your Work visa isn't issued yet, you can never know.. Work visa itself might take between 3 days to 2 months..