“Production” means you are producing content and receiving monetary rewards. For example, selling albums, producing sound tracks for a commercial / broadcast / TV program and running ads on your published contents.
From what @khuasw said, it seems that:
Yes, non-commercial use is allowed. But if you want commercial usage or advertisements to appear on or with your content, maybe even a sponsorship require a proper license. Even then, some commercial restrictions may apply. So you have to look into it further for each voicebank. The terms of service might be useful ^^
It’s fine to upload covers and originals without monetization, with monetization up to a certain point is fine too (I think something around $600-700USD?). After that point you should contact Animen about it as they hold the rights to the characters. For Renri I’m not sure, sorry. You’d need to check her TOS on her official website.