Jailbreak is a term used in iPhone models. Blackberry mobile models doesn't require a jailbreak. What is the exact problem with your play book?
You won't be having any problem in adding third party apps for a Blackberry. If at all you are not able to add third party apps, It must be a problem with your anti virus protection. Turn off privacy to add third party apps. Or if you need to unlock your phone from network restriction, You need to enter it's unique unlock code. You can purchase such code from Unbblock.com