The usage of the term “6” in rap was mainly because of Drake. 6 refers to Toronto, Canada, which is Drake’s home turf. The exact origins of it are still unknown, but it has been connected to the area phone numbers and the number of localities in Toronto. One might say:
The 6 won the NBA finals with Kawhi Leonard in 2019.
The constant usage of Drake, along with his immense popularity, has allowed the term to soar to an insane level of popularity. It is recognized by many, especially the people of Toronto. Basketball fans even refer to the Toronto Raptors as 6 because of this.