In the Installation information, we convey that RedHat Linux 9 support was introduced in version 6.0.4.

https://www.mongodb.com/docs/manual/tutorial/install-mongodb-enterprise-on-red-hat/#platform-support

However, in the release notes, we convey that RedHat Linux 9 support was introduced in version 6.0.3.

https://www.mongodb.com/docs/manual/release-notes/6.0/#platform-support