How many wifi streams does the Macbook Pro support?

I'm referring to the Macbook Pro Retina 15-inch (2013) model. I read that it supports three streams, and that it supports both 2.4Ghz and 5Ghz.

The question is: does it support three streams on both 2.4Ghz and 5Ghz, for a total of 6 streams? If not, how many streams does it support at 2.4Ghz, and how many at 5Ghz?

I'm looking at buying a router, so I want to make sure that the router supports as many streams at each frequency as the Macbook does. Thanks.