The short answer is no. Rockstar Games never released an official version of Grand Theft Auto V for the PlayStation Portable.

However, before you attempt to download any files, it is crucial to understand the technical reality of GTA 5 on the PSP and what these "updated" ISO files actually represent. The Technical Reality: Did GTA 5 Ever Come to PSP?

New Radio Stations: Modern music tracks added to the game files. How to Safely Play GTA on the Go

Malicious FilesBecause the demand for GTA 5 on mobile and handhelds is so high, many sites use these keywords to trick users into downloading malware, adware, or survey-locked files. Always exercise extreme caution when downloading unofficial ISOs from third-party clubs. Features of GTA 5 PSP "Updated" Mods

Vehicle Packs: Modern cars like the Zentorno or Adder ported into the old engine.

If you want a genuine GTA experience on a handheld device, there are better alternatives than searching for non-existent PSP ports: