As suggested by outreach program mentors from previous rounds of GSOC/Outreachy in T150732, we decided to use Zulip for the new rounds.
They also shared with us some guides that helped us in geting started & following best community building practices. Links are below:
In about a month or so, we are nearing to the completion of the GSOC/Outreachy rounds and we would like to evaluate Zulip as a mentoring tool. We are planning on asking students and mentors, some specific questions via a program feedback survey that will help us evaluate the usefulness of the tool in the context of our outreach programs.
After consolidating the results, we will decide what our next steps are on this!