The specifically refers to the second disc required for the Xbox 360 version of the game in the Japanese region. Unlike modern versions, the original Xbox 360 release was distributed across two DVDs: Disc 1 (Install) and Disc 2 (Play) . Overview of Disc 2 (Play Disc)
To run the game on a modified Xbox 360, you must extract the contents of both discs. Download Grand Theft Auto V -Japan- -Disc 2- -P...
Ensure you have enough storage space on your device or console. GTA V requires a significant amount of space. The specifically refers to the second disc required
If you are looking to "download" this version rather than using physical discs, you can access it through modern digital storefronts: Download Grand Theft Auto V -Japan- -Disc 2- -P...