I walked by TKTS the4 other night to check. I could have sworn I had seen it there this summer. But, nothing was up. I don't know if performances had started already and it just wasn't up, or if it hadn't started yet. If I walk by again soon, I'll check for you. But, again, they would have to be same day tickets.
Your better bet, if you really want to go is probably to order them in advance.