Hi Sir!
After your contest's initial "Open" phase closes, it will enter the "Top 5" phase; only the top 5 ranked Designers will be able to submit revisions at that time.
The "Top 5" Designers are the first 5 Designers in a contest, not the first 5 designs.
When "Top 5" ends, the "Judging" phase begins. The Designer of the 1st place design will be the only Designer who can submit revisions at that time.
You can get more ideas of how the site works here; simply type in the search bar:
https://logotournament.com/help/client