To play GTA V on Dolphin, you would typically need:

Grand Theft Auto V cannot run on the Dolphin Emulator because Dolphin is specifically designed for Nintendo GameCube and Wii hardware , while GTA V was never released for those consoles. Why You Won't Find a Link Platform Incompatibility

Buy GTA V from a digital storefront like Steam, Epic Games Store, or directly from Rockstar Games.

: Sites offering fake ISOs are common sources for harmful software.