It looks like your photo is taken at an angle which initially made identification of the problem "hazy" and the bolt that is "leaking" is one that holds the inspection cover over the convertor housing. This cover does not have any seal as its only purpose is to cover a rotating torque convertor from getting mixed up with road debris etc. I'd tighten up the bolt as it clearly is loose. As to it leaking oil, it cannot be transmission oil as the pan is a good 200mm lower, so it must be engine oil and as that cover does not act as a seal then the oil is coming from somewhere else. From the picture the leak is not bad or terminal....maybe it is leaking from somewhere else and appearing there???
If it was me I would firstly tighten the bolt, secondly spray some degreaser over the area to clean it properly and thirdly I would check it again in a few days. Remember that most cars leak or weep a bit of oil....its a fact of life. Take some pix after a week and post. Good Luck.