Keep in mind we don't have a specific function for attendance tracking but there are ways to use TIC to gather some information.
If you're wanting to track attendance for a particular event, we can do that quite easily by creating a Group and setting the automated reply type to "Simple Reply".
This way anytime someone texts your keyword they will be added to the Group and thus we know they attended. A Simple Reply will not ask for additional information, but simply gather their phone number (if not already in your TIC account) and add them to the group associated with the keyword.
On the Groups page, you will see the count for the number of people in each group. We can also contact them after the event by sending a message to everyone in the group.
Remember, that this can only get you a ballpark idea as some might not text in, but if you are wanting general figures of who attended, or if you want to have them RSVP in advance to get an idea for event supplies this would work well.