To see if you have BizTalk Rules Engine configured, bring up the "BizTalk Server Configuration" Tool and check under the "Business Rules Engine" node.

To install BizTalk Business Rule Engine, start BizTalk installation. Once you get to the screen that shows the available components, check under "Additional Software" and select "Business Rules Components".

After installation, you’ll need to go back to “BizTalk Server Configuration” Tool to configure the database and service account information.
 
Once everything is done, you’ll see the following items in your “Programs”:
Business Rule Composer
Business Rules Engine Deployment Wizard