Every SEMrush Project has the ability to create one Position Tracking campaign. Depending on the level of your SEMrush account, you will have limits on the number of keywords you can track and the number of extra devices and locations tracked in your campaign.
All levels can track up to 20 competitors in a Position Tracking campaign. So between all of your projects a free account can track 20 total competitors, a Pro account can track up to 100 competitors, a Guru account can track up to1000 competitors, and a Business account can track up to 4,000 competitors.
Users can manage their limits from the Manage Accounts area of their profile.