how to find out which community tags does ultimate version build on?

Ultimate and Community versions match.

IU-173.4674.33 corresponds to IC-173.4674.33, the corresponding tag is 173.4674

Not sure I understand the question.

It is just a tag, available as any other tag in the Intellij corepositorypositroy

https://github.com/JetBrains/intellij-community

Tag name convention is product/build.number. So in IDEA the exact tag name is idea/173.4674

thanks for your answer . I wonder where I can find the information of the versions match ?

oh, the Ultimate version's prefix is the same as the version of community , and the tag is the number of the prefix

Is that right?

IU-173.4674.33

IC-173.4674.33

the prefix 173.4674 is the tag name

thanks a lot