My Corporation has about 100 people. I don’t need anything in the Rocketchat Pro, except the users limited
It helps us to help you if you give us some server details.
You have two choices.
Community Edition or subscription.
Starter is fully featured up to 25 users. That limit is not going to change.
Why? Lots of big companies used Rocket.Chat for free, and never contributed anything back. Not a line of code, help in the forums, documentation or anything. Many of them even sold Rocket to other people and charged them for it, and still contributed nothing back!
So like many open source companies, Rocket.Chat had to decide how to stay in business because they were essentially building software for other people to profit from, and were losing money themselves. If they had gone out of business then no one gets any software!
Quite simply bigger companies have more money, and ability to pay.
So you can either use Community Edition as modify as you wish under the MIT Licence, or you if you are a bigger company then you need to pay for a subscription.
That may not be what you want to hear, but that is the answer.