We have a channel set up specifically for students (and other community members) working with us on Summer of Code projects. Please join us on #plan9-gsoc.
We have had other channels in the past, such as #plan9-social and #plan9-gsoc-mentors, but those were either never heavily used or were short-lived; they are not monitored.
We maintained a presence on Freenode for many years, until the hostile takeover and mass departure of all the staff. We would discourage you from using those channels.