The short answer is yes. You can add rules to your configuration to track the users logged-in at the same time (concurrent users) and refuse new connections if the number of the concurrent users exceeds a certain limit. Alternatively, you can track the number of registered users (but not necessarily logged-in at the same time) like Employee, and refuse new user registration if the number of registered users exceeds a certain limit. Let me know if you need more information on how this can be done.
Please also note that Aware IM Runtime includes 5 named user (seat) licenses. If any of your clients have more than 5 employees within the organization using your Aware IM application (not necessarily logged-in at the same time), you should purchase an additional named user license for each user in excess of 5.
