If you are looking to watch this legally, Friends is currently streaming in HD on Max (formerly HBO Max). The streaming versions are remastered in 1080p, though they usually use the shorter broadcast edits rather than the extended DVD versions.
This is the name of the "release group" that encoded the video. Watch Friends s06e04 dvdrip x264-sonix-1
Since you're looking for this particular episode, here is a quick breakdown of what happens in that chapter of the show, along with some context on that specific file format: Episode Recap: "The One Where Joey Loses His Insurance" If you are looking to watch this legally,
Joey develops a painful hernia right after his health insurance expires. To avoid paying the hospital bill, he tries to "act" through the pain during auditions, leading to some of Matt LeBlanc's funniest physical comedy. Since you're looking for this particular episode, here
This is the compression standard (codec) used, known for keeping high visual quality while maintaining a smaller file size.
Rachel finds out that Ross never actually filed the paperwork for their annulment, meaning they are still legally married. Technical Note: x264-SONIX
Ross is invited to give a guest lecture at NYU. Nervous about being boring, he adopts a bizarre, fake English accent that he then struggles to phase out as the lecture continues.