You need the compiled VPK file for the Vita port.
: As of 2025, there is a "Revisited Trilogy" update (v1.5) that provides a unified launcher for GTA 3, Vice City, and San Andreas from a single bubble. Core Installation Requirements gta 3 vpk ps vita work
Without specific details on the VPK file you're referring to, such as its source or how it was created, it's challenging to provide a definitive review. However, if you're considering playing GTA 3 on your PS Vita: You need the compiled VPK file for the Vita port