5 Poppin 6 Droppin is a slang term used by Chicago gangs, as well as gangs that have adopted some Chicago gang lits. This term gained notoriety in New York due to some gang members asking random individuals "what's popping", and then proceeding to slash their face if they failed to answer "5 popping 6 droppin."
Gangs who use this term have a 5-pointed star symbol, while their rivals have a 6-pointed star symbol. The 5/6-pointed star symbol started in Chicago after the creation of the People and Folk Nation alliances. The People nation have a 5-pointed star as one of their main symbols, while the Folk Nation have a 6-pointed star symbol. Gangs whom are members of the people nation will often say "5 Popping 6 Dropping" to greet other members or to simply rep their nation. The term literally means that "Folk Nation is shooting (popping) and the People Nation is dying (dropping). Members of the Folk nation say the opposite, "6 Poppin, 5 Droppin."
Though the term started in Chicago, when Bloods moved to the East Coast and OG Mack formed what would later be known as the United Blood Nation (UBN), they adopted some symbols that were used by Chicago gangs, respectively the 5 and 6-pointed stars. Crip gang members use the 6-pointed star, while Blood gang members use the 5-pointed star. When Blood gang members say 5 popping 6 droppin, they're literally saying "Bloods are shooting (popping), while Crips are dying (dropping). Blood gang members sometimes add extra lines and say "5 poppin 6 droppin. Crip Killer 'til my casket get drop, 5 alive 6 must die rest in peace to OG ty.
Crip gang members say the opposite, 6 poppin 5 droppin. Only Bloods and Crips not in LA use this saying, those from LA do not rep the 5/6-pointed stars.