There is no Season 15. The show concluded with a 12-episode final season that wrapped up the "No Man's Land" storyline and gave us the time jump into the full Batman persona.
The " Gotham Season 15 " Blu-ray release you are referring to does not exist. The TV series Gotham gotham season 15 complete bluray 720p repack
In file-sharing communities, a "repack" usually refers to a compressed version of a release, but since there is no season 15, the name itself is technically incorrect. There is no Season 15
By downloading or purchasing the Gotham Season 15 Complete BluRay 720p Repack, fans can experience the thrill of the series in stunning high definition. With its rich narrative, memorable characters, and exceptional production values, Gotham is an excellent addition to any home entertainment collection. The TV series Gotham Unofficial "Repack": In file-sharing
This indicates that the original release had a technical error (like out-of-sync audio or a missing scene) that was fixed and re-released by the group that encoded it. 720p BluRay: