Which gasket is this that is leaking?

When I was underneath my 2006 3.3L V6 Toyota Highlander doing work I noticed some oil leaking from a gasket (shown by green arrow in image below). Can someone tell me which gasket this is? Thanks

Looks like transmission oil but I could be wrong.What is the color of the liquid?

My best guess is the leak is at the center differential case mount. I’m assuming it’s an all wheel drive.

That is the all wheel drive transfer unit, the cover is sealed with Form-In-Place-Gasket (RTV).

The transmission must be removed before the transfer unit can be separated from the transmission, a 15 hour job to real that cover.

I have seen many of those seep gear oil, I would top off the level and check the level at each oil change.