Hi @rohan23, thank you for your question.
There are no user limits on the Mattermost community version, but you may want to check that your Max Users per Team setting is configured high enough to allow that many users. The limit is there so that administrators can scale their system based on hardware requirements.
With that said, it appears you increased the limit, but the user is still facing this issue. If so, are you open to sharing a screenshot of the error that is shown, and we’ll aim to troubleshoot the issue with you?