I had a XBOX One Power adapter and wanted to check if it could be used for my 360, as users mentioned earlier, the pin shape is different and it wouldn’t fit. Saw a video which mentioned that the pins could be cut and swapped. It took me only 5 minutes, my 360 power adapter was dead, so wanted to take a chance and it works perfectly. In summary we can use XBOX one power adaptor for XBOX 360 after cutting the wires and changing the pins.
https://www.youtube.com/watch?v=rskqK_k8rOE