Commando droid most likely, it's reflexes are too fast for him, if he gets a lucky shot he could win though, but realistically the commando droid would shoot the blaster out of his hand then proceed slice him with the vibroblade, the only people to take on commando droids and win are jedi are experienced clones
Yeah, he dropped a few of them in a hotel Ambush in a lower part of Coruscant
__________________ "Happiness is a lie. Life is horror. The light is always dying all across the universe. The last star will flicker out someday, when it does, all that remains is shadow. And I will be its king!"'-Amahl Farouk
This is him as of ANH though, so that shouldn't count.
But then again...considering he's older there....but nah can just disregard that really. Doesn't really need much considering his aim and skill with a blaster anyhow.
That being said, Han can get this on his fast draw and dead aim. His blaster, DL-44 is already a powerful blaster factory stock, Han took that and modified it to make it even moreso.
So damaging the Commando Droid isn't much an issue. There isn't much room for the droid to maneuver either inside the Falcon, so it's not gonna be pulling out any fancy agility stunts.