What do you call the thing that "holds" the iron man armors? I say "hold", because it doesn't seem to be a container, but more like a sort of stand. Not sure if there's a name for it, because it's not a stand.
It's difficult to say what Tony Stark calls the individual structures holding his suits, because their function is not clear. They are not required for support, since the suits can stand on their own, and isn't used for recharging because the suits are self-powered.
That being said: One possibility is to call them a "dock", or a "docking station", much the same as some devices that you can use to recharge a cell phone.
On the other hand, because they serve no real function, it's not entirely wrong to call it a "display cabinet", much like a fan would use to show off a collection of Iron Man action figures:
Individual spaces in a display cabinet may be called "slots", "spaces", "openings", "niches", or various other similar terms.
(Edit) I agree that these can be individually called "stands", or collectively a "rack" of similar objects all hung together. On that note: For whatever reason, a building where aircraft are kept is called a "hangar", which also makes sense for Iron Man's suits.
If it his wardrobe that can refer to the place where the suits are stored and to the collection of suits!
1 A large, tall cupboard or recess in which clothes may be hung or stored.
Many kids are scared of monsters under the bed, ogres and bogeymen lurking in wardrobes and the cupboard under the stairs.
1.1 A person's entire collection of clothes.
The entire three-quarters of my wardrobe was black.
Because these spaces are open (without doors), they can be considered "niches" within a "closet". Many houses built in the past 40 years in the United States have huge "walk-in closets" that can be used as "dressing areas".
Many Massachusetts Institute of Technology dormitory bedrooms do not have built-in closets. Instead, they have pieces of furniture, which are roughly three feet wide by two feet deep by seven feet tall. These pieces of furniture have very sturdy curtains that can be used to hide their contents. MIT students call them "elephants", because they are larger than "trunks".