Which kernel to use for Note 4?

[DroidH]

Hi
Which kernel would I use when rooting my Note 4 N910F out of the following?
1. Emotion-TW-5.1.1-nightly-r20-RC1-SM-N910F
2.Emotion-TW-5.1.1-nightly-r21-RC1-SM-N910F
3. Emotion-TW-nightly-r23-RC1-SM-N910F
4. Emotion-TW-nightly-r23-RC1-SM-N910F_ZEROLEMON

What exactly does R and RC mean?
Thanks