Quantize is a function of MIDI.

In RB you can use the Audio Edit window and zoom in to a section, highlight it, and drag it a small amount to line up where you want it by holding down the CTRL button and dragging the section.
That way you can line up the waveform peaks with the lines for the bars, which is what Quantizing would do ..

I do not work here, but the benefits are still awesome
Make your sound your own!