Yes, in some comic storylines, the Joker is presented as a sort of twisted 'brother' figure to Batman, but it's not a straightforward familial relationship.
Yes, in some comic storylines, the Joker is depicted as a sort of twisted 'brother' figure to Batman, but it's a complex and unconventional relationship.
Not typically. While there have been alternate takes and complex story arcs that explore a deeper connection between Joker and Batman, being actual brothers is not a common or core element of their relationship in most Batman comics.
In most comic versions, the Joker and Batman have no direct family relationship. They are more like arch-enemies with a complex adversarial dynamic rather than being related by blood.
It's a bit complicated. Sometimes in comics, there are hints or storylines that imply a strange, dysfunctional 'brotherhood' between Joker and Batman. But it's not a straightforward or definite thing throughout all Batman comic universes.