These guys will appear during the overseer bossfight, in the lunar biome on genesis and during the vr master controller (or just VR rockwell) and they are hella cocky, they will damage you from your mount, they don't do really high damage and with armor they do very low to 0 damage but they will slowly drain your armor's durability, best way to take care of them snipers are best suggested, if you really want you can use other ranged weapon or creatures with ranged attacks like velonas (if the drones are on top of you then you still wanna use your ranged weapons), and all I can say is that they are the cockiest of the robots

More Attack Drone Encountering Tips