To play "Resident Evil 6" (or any PSP game) on PPSSPP, you need a game ROM. While there are various sites offering PSP game downloads, : downloading ROMs for games you don't own can infringe on copyright laws.
To download Resident Evil 6 PPSSPP for Android, follow these steps: Resident Evil 6 Ppsspp Android Game Download WORK
If you own the game on Steam or Xbox, you can use services like GeForce NOW or Xbox Cloud Gaming . This streams the actual PC/Console version to your phone. To play "Resident Evil 6" (or any PSP