How many teams can qualify for Berlin in NA

Is it the Top 4 from upper or lower bracket or whoever wins the lower bracket finals and moves to grands?

Three teams from NA can qualify for Berlin.

The two teams in the Upper Final are locked in. If one of them loses their next two matches, they place 3rd at minimum, which still qualifies.

The third team going to Berlin will be whichever team from the lower bracket reaches the Lower Final, where they'll face the loser of 100T v SEN.

if you're thinking of the weird case where sentinels can force it into 4 teams from NA, you're thinking of Valorant Champions

tldr lower round 3 winner makes it berlin