Mahindra has been in the market a very long time and is doing as well as any tractor manufacturer could be, I don't think support will go away. A lot of their knowledge came from building machines for International. They have strong partnerships with industry leaders like Perkins, Mitsubishi, Bosch, and many others. They sell more tractors worldwide than anyone else. They have a solid business going on.
TYM has also been around a long time and has built tractors sold under several nameplates, they have even built tractors sold with the Mahindra name on them. When TYM first started, they mimicked a lot of the Iseki designs (which are great designs as well, Iseki made tractors sold under many names too). If the TYM has more of what you need, go for it. Honestly I'd not hesitate with either.
With the short wheelbase of the 3535, the low ground clearance isn't a huge issue unless you really plan on beating the tractor over some big rocks and climbing over downed trees. Even then, the lowest point is the loader frame which will not be easily damaged. The only concern might be a fuel tank puncture from a stick or a stick grabbing a line somewhere, but honestly sticks come in longer lengths than the highest of ground clearances that tractors come with. Few inches of extra clearance doesn't mean you can be less careful during operation. I generally use my bucket to clear a path for the tires, which in turn keeps things away from the fuel tank and hoses as well. I'm more concerned about things busting a tire than something reaching up and grabbing lines, poking holes, or causing some sort of underside damage.
RedM or TYM you'll have a capable machine, just be as capable of an operator as the machine is, and go slow and easy. You can't do work with a tractor so slowly that it is either faster or more cost efficient for one man to do it by hand.