I am not certain on the type or amount of oil, but most tractors of that vintage and newer use a combination hydraulic/transmission fluid. One of the universal fluids should work as long as it meets the tractor manufacturer's specifications. I'd call a Massey Ferguson dealer and ask if you aren't sure. They can look up the specs and make sure you are getting the correct oil. Using the incorrect oil can cause serious problems if you have a power shift or other type of hydraulically shifted transmission that most newer tractors use. If you have an owner's manual for the tractor, it should list the specification for the oil. You can match that specification to the oil (usually listed on the label on the container). The specification is usually listed as a number or combination of letters and numbers as shown on this website:
Kubota UDT/SuperUDT Specifications There they list the specifications that their oil meets, including some for Massey Ferguson. Again, you will need to either ask at a dealer or look in the manual to get the specification number you need.
According to the Massey Ferguson website, the closest dealer to you is:
KMETIJSKA MEHANIZACIJA TRBOJE D.O.O.
Trboje 10,
SLOVENIA,
Kranj,
SLOVENIA,
4000
Tel: 386 64 49 1565
Fax: 386 64 49 5011
Hope this helps, and welcome to the forum!!