Why would Iran even bother with drones when they have many missile types and an IRBM that could easily pack a nuke?
An IRBM can easily pack a nuke if you’re capable of producing a nuke that can sit on the head of an IRBM. And if you have the HEU to make it. Iran currently has neither.
They could make a dirty bomb *if* they can get the material.
Iran’s IRBMs are estimated at 750-1500kg payload capacity. Little Boy was over 4000kg, and Fat Man was a little larger at about 4700kg. Iran isn’t at the sophistication of Little Boy or Fat Man yet, and they don’t have access to the HEU they’ve produced so far.
There’s a lot of talk about “mini-bombs” but see earlier discussion on realism there. You can make a smaller core than Little Man, but not much smaller and it still be useful, and the issue is the entire payload, not the core, from the standpoint of delivery. Iran doesn’t have the miniiaturization capability needed for this.