Hey!
If you need 6 ohm than that would be the 6R0.

Not sure what R stand for myself but....
6R0 = 6.0Ω, 6R2 = 6.2Ω and so on.
Make sure to get the right wattage for you app.

BTW... I like Caddock resistor. I use mostly the MK132 in my pre and amps.
Take care,
Buddy