Which directory can i find the models.py and also admin.py?

Adding code to misago’s models.py doesn’t sound right to me. What are you trying to accomplish?

To add django-meta app to misago models, you will have to fork Misago and maintain custom codebase. This means you will have to maintain database migration files, merge in fixes and changes from main repository, etc. ect.

Also to keep on mind is that Misago has custom-build admin control panel, so you would have to customize it too to add controls for editing metadata.

Lastly, I am aware of value of customizing threads/categories metadata for SEO reasons and would like to provide features enabling forum team to customize those if required. I’m just tied by other work before I could get to it :(