If you're having trouble, I can help you troubleshoot. Are you seeing an like "Download failed because you may not have purchased this app," or is the game crashing on startup ?
Setting up the game requires manually placing the OBB file into a specific system directory on your Android device.
Opt for well-known torrent sites or forums that are recognized for hosting game torrents. Even so, proceed with caution.
Many sites offering “full OBB download” for GTA SA contain malware. Always use official app stores.