Antlers are extensions of the skull grown by members of the deer family.
They are not true bone structures but they usually grow in symmetrical pairs.
In most species, only the male grows antlers with the exception of Caribou and the antlers primarily function in sexual selection as attractions to females and as weapons in fights for control of harems.
So can rabbits eat antlers at all?
Unfortunately they can’t.
Bunnies cannot eat any items that have excess proteins and animal fats that antlers will have.
If they see them around, then they will want to eat them, but the really should be avoided as a food for them.
Even antler chews that you find in pet stores. There are better foods and chews for your bunny.