You can find all information there:
https://www.eurobot.org/how-to-participate-to-eurobot-finals/
Registration process is the same for Eurobot and Eurobot Junior, you just have to select the corresponding contest on the registration software.
The deadline for independent teams was on December 31th, but I checked it was not clearly written on the website, we have to fix that!
But don't worry, we have a process for late registrations, you can send an email to registration@eurobot.org with your contact information, we can still register your team.