The first seven sets will include episodes 1-175 (the first Fairy Tail anime) and sets eight through 11 will contain episodes 176-277 (the second FairyTail anime, including Fairy Tail Zero).
The official website for the Fairy Tail anime posted details, including episode counts, for a “Fairy Tail Ultimate Collection” series of Blu-ray Disc releases that will cover all of the Fairy Tail television anime.
The final two sets are listed with a “planned” 26 and 25 episodes, respectively, implying that the third series is planned for a total of 51 episodes.
The latest and final anime season based on Hiro Mashima’s manga premiered in Japan on October 7, and Crunchyroll and Funimation are streaming the anime with English subtitles.