[ozrien]

The Units are explained in Section 17. Quad. Encoder units are in Section 17.1.
They are in 4X units.

Examples for reading the encoder? That would be a one line example...
int quadEncPos = motorController.getEncPosition(); /* section 5 */

You can also sanity check the values without code changes by using the Self-Test (section 2.4).

How do you plan on using the encoders exactly? Do you want to setup the Talon SRX to internally closed-loop position and/or velocity? Or do you just want to retrieve the encoder values so your logic in the RIO can make it's own decisions (for example doing a closed-loop in the RIO).

I think once you make that clear, then the community can give you better answers.