Ok, I think that's better to give some info about where you're coming from. Most guys here take pride in carving the curves, which is rider skill than straight drag, which is mostly about bike's potential.
Anyway, street racing is illegal and dangerous, and blah, etc. But in matter of performance, it's hard to judge since 06 R6 isn't available everywhere and hasn't be compared in magazine shootouts. Also, I'm not sure how much lighter or power to the rear wheel R6 is making this year. But my long guess is GSXR750 still should have advantage, it's relatively light, and has more torque midrange to take it to top-end and still has more HP than last year's ZX-6R.
However, those are bike's potential, as a rider, if you blow off a good launch, poor clutch skills and clutchless upshifts, all those things can affect your RT, and ultimately lose the race.