RN stands for real nigga. A real nigga is a nigga that doesn't do pussy nigga shit, obeys the real nigga laws and the laws of the streets, and doesn't switch up on his homies ever. Another meaning for rn is right now.
1:
Damn that nigga getting attacked by some dogs I wonder what he finna do.
That Nigga: (eats the dog)
Damn that nigga ain't no pussy nigga hes different. (that nigga just asian he ain't no real nigga)

2:

Hoe: Mom my boyfriend just nutted in my eye rn will it be fine?
Mom: Nah bitch, you a hoe.
by TheOfficialRN October 21, 2020
Stands for Real Nigga Shit. A phrase used when someone wants to add emphasis to the fact that the thing they just said was, indeed, true. It is a phrase or sentence someone says that is so true it deserves to have "Real Nigga Shit" at the end of it.
Aye man if you come in my face like that again I'm knocking yo ass out, Real Nigga shit(RNS)!
by BossShit101 March 19, 2011
shortcut for "right now", commonly used by lazy fatasses or some drunk fucks.

...or teens.
by Veridicule December 27, 2018
Real Nigga shit, often used when talking about people possibly on kik facebook came from word Bitch nigga
Girl:Dude she look so ratchet

Girl:Real Nigga Shit Or Rns
by LauraDoee June 4, 2014
Used when trying to assure someone that something is the truth:

RNS dude I swear that girl with the fatty winked at me yesterday.
by Bigppancakes45 April 6, 2016