Well that is what we call "totes" around here... English is a wonderful language, we have so many regional variations even here in the US, we can barely communicate with some areas. Let alone you guys in other countries, when it comes to naming things, I am certain that I would be scratching my head trying to decipher some of your local names for objects. But in any case, yes a large plastic storage container is what I had in mind for catching 10+ gallons of hydraulic fluid.
I don't know about your tractor, but the Kioti has a huge main drain plug in the middle of the transmission, and the flow rate is very rapid. Then you have the rear final drive plugs on the rear axle which are much smaller plugs.