tractors you cite this would be my order from best to worst (caution, perhaps the best brand manufactures tractors in one continent or another continent and the opinion is different depending on the continent where you live).
1-john deree .......... very good tractor, for many years has been the best tractor in the world.
2-Case and New Holland ....... very good tractor can improve the details, but that aregla with powerful engines cummings, cummings is a manufacturer of motors of ships or aircraft, that experience makes Case and New Holland have engines very robust and reliable
3-massey ferguson, has long been the best or the second best tractor thanks to its perkins engine, currently is staying a bit back and have a little dated technology
4-kubota, in my country is considered a normal tractor, far outweighed by other tractors, in my country there was a brand of tractors called ebro and was bought by kubota, ebro was quite an old tractor, so maybe we're not being fair and thinking in kubota think ebro
5-bielarus, this is the worst I've seen tractor in my life, is all iron and more iron, a few months ago I saw one of its latest models and looked like a tractor manufactured in 1960
?-mahindra, I can not comment, I do not know this brand
......................... A very inportant advice is that if someone is going to buy a tractor, choose a good brand, but it is also very important that that mark has workshop or technical service near you and you can have access to spare parts easily