Sorry, I am not quite sure what you mean. Hopefully the following helps:
If you are asking about the free editions of NetWorx (version 5.5.5 and older), yes those can be used in a commercial environment. Those versions were free and there was no restriction on their use in business environment.
If you are asking if you can install a free trial copy of the latest NetWorx version, yes you can do that too. You can download and use it for free for trial purposes for 30 days. After that, if you want to keep using it, you will need to purchase a business licence.