I suppose you are installing this on a mini-ITX mobo in a tiny case. If not get a different cooler.
How much you CAN overclock is more depending on the CPU itself and how far you are willing to push the temps. Throtteling starts only at 105°, but I wouldn't let my CPU near that temp. If you're OK with torturing your CPU and probably severely shortening it's lifetime then you can push it till the bleeding edge of thermal limits, otherwise you should keep a safe distance. Generally it's stated you should keep it under 85° during stress test and under 75° during daily usage. How far you'll get with that cooler is very much depending on how much voltage you need for your desired OC.
For sure it ain't the best air cooler out there, but that's a given because of the design. For top performance you'll need a dual tower like NH-D15.