Nope, they wait until teams form!

"It's a good thing we're partners," Pyrrha smiled as they got off the bullhead. "We're now guaranteed to share the same dorm together!"

Jaune smiled and nodded as they turned in the chess piece they collected to Glynda Goodwitch, who looked it over and nodded, and they were led to the auditorium for the team assignment ceremony once they were confirmed to have passed the test.

Ozpin got on the stage, and began the announcements. It turned out that teams were decided by the pairs choosing the chess pieces. There were two of each piece, so whichever pairs had the matching set would be put in the team of four. As such, Ruby and Weiss were teamed up with Yang and Blake, Ruby named Team Leader, the team name being RWBY (Ruby), funnily enough.

It was then announced that his team was with Nora and Ren, which he was fine with, given they proved to work well together. He was absolutely shocked to hear that he was named Team Leader, and his team was named JNPR (Juniper). Ozpin simply sent him a smile and a congratulations.

...

After the ceremony concluded, they headed to their new dorms, and unpacked, Jaune's could hear a loud argument over in RWBY's dorm. It was pretty muffled through the walls and not quite loud enough to make out exact details, but from the sound of it, someone had brought way more stuff than they could reasonably accommodate with the others. Jaune suspected Weiss.

Jaune and Pyrrha started getting to know Ren and Nora. They seemed to have been friends for a good long while, though Ren seemed quite exhausted by Nora's... Exuberance. "Does she have an off switch?" Jaune asked Ren as they and Pyrrha watched her move around the room in an energetic manner, unpacking her things and trying to figure out how best to arrange them. She moved between several different combinations at dizzying speeds.

"If she does, I have yet to find it," Ren sighed.

"...not for lack of trying, I'm sure," Jaune chuckled, getting a wry smirk from Ren, and a giggle from Pyrrha.