I'm sick the Mobb rolls thick
The name Mobb Deep came about because Prodigy, Havoc and everyone up in the bridge “mobbed deep”, meaning they always ran around with a large entourage.
In this line, “thick” basically means the same thing as “deep”. Hav is just saying that he and Prodigy will always be rolling around with their homies.
To help improve the meaning of these lyrics, visit “The Start Of Your Ending (41st Side)” by Mobb Deep Lyrics and leave a comment on the lyrics box