In The Outsiders, what does Ponyboy mean when he says the Socs are “reeling pickled” on page 54?

"Reeling pickled," as used in The Outsiders, is a slang phrase for describing extreme drunkenness. Reeling is a term that is generally used to describe someone who is off-balance or otherwise having difficulty maintaining a solid footing. It is usually used now in an emotional sense—i.e., a big surprise that left someone reeling. However, it can also describe an individual who is having difficulty maintaining their balance or composure. Someone who is stumbling and acting wildly emotional could be described as reeling.
The term "pickled" was more common at the time the book is set, but it has fallen out of favor lately. It generally refers to someone who is very intoxicated and is meant to illustrate the idea that the individual has consumed enough alcohol to actually pickle himself. Being pickled does not necessarily equate with stumbling or aggression, as an individual could be described as pickled shortly after passing out or if he were intoxicated due to depression. It could also describe a exuberantly drunken person.
Together, these words seek to describe the Socs as not only very intoxicated, but intoxicated in a manner that has left them stumbling, uncoordinated, and wildly emotional. This helps identify the danger that Ponyboy and Johnny are in as individuals in this state will be unlikely to control their actions.

In chapter 4, Ponyboy runs away from home and meets up with Johnny at the park. While they are hanging out at the park, a group of Socs arrive in a blue Mustang and get out of the car. As the Socs approach Pony and Johnny, Pony sees that they are staggering and figures that they are "reeling pickled." According to the Merriam-Webster online dictionary, the word "reeling" means to stagger and lurch violently. The term "pickled" is an idiom used to describe someone extremely intoxicated. Essentially, Ponyboy is saying that the five Socs approaching them are completely drunk. Bob Sheldon proceeds to hold Ponyboy's head underneath the water in the park's fountain, and Johnny stabs Bob in self-defense. Johnny ends up killing Bob Sheldon, and they are forced to skip town in order to avoid being arrested.