The Daleks would have completely wiped the Borg out, of course.
That doesn't seem likely. The Daleks pretty much have just one strategy -- zap everything -- and Borg generally adapt to weapons fire after 2-3 shots at most. I envision the Daleks futilely blasting away and screaming as the Borg close in on them -- and assimilate the Daleks
. And then everyone's in trouble.
I'm not sure how the Borg nanotubules would reach a Dalek mutant inside its travel machine.
The Borg control one part of the Delta Quadrant. The Dalek Empire spans an entire galaxy. (Not Mutter's Spiral, obviously.) The Daleks win on sheer numbers.