The schedule of CSW side events on UN premises is now available at http://www.unwomen.org/en/csw/csw59-2015/side-events/calendar-of-side-events
NGOs with valid UN grounds passes need not indicate prior interest in attending events unless specified by event sponsors. Side events on UN premises are not ticketed this year unless they are by invitation only. Please check the schedule page frequently as times and venues of side events may change."
It is recommend that people register for the events that require prior registration asap as they tend to fill up quickly.