It is accessaible to tour there and you can participate a group or travel as individule, however, better not to travel alone. The middle part of Tiger leaping Gorge is closed for the road construction. In fact, I am not sure if it can be finishes in September. You can get to the upper Tilger Leaping Gorge or hiking to middle part is also available.
As to tours, you can read this for reference.
https://www.travelchinaguide.com/package/tour-lj03.htm