You can see all information regarding purchasing tickets online or in person, here.
UPDATE: According to @cameron_tiff - Kristen is officially attending the festival on September 6, 2012.
Interested parties: 1 addition to our
#TIFF12 guest list: Kristen Stewart for ON THE ROAD
— Cameron Bailey (@cameron_tiff) August 21, 2012
Timings: 6/9 Red Carpet Premiere is 9PM ET/ 6PM PT/ (2AM BST/ 3AM CET Friday Morning) Screenings: 6/9 at 1:45PM ET & 9PM ET (Red Carpet Premiere). 7/9 at 11:30AM ET (Thanks Gossipgyal)Possbile Livestream HERE (Via) and HERE (Via)