The file is a .cia , which is designed to be installed directly to the Nintendo 3DS SD card via FBI, making it appear as a legitimate game on the home screen.
The file is sourced from Ziperto , a widely used repository for 3DS custom firmware users. Usage Guide: Place the file: Copy the .cia file to your 3DS SD card.
If you provide this, I can tell you if it's a known reliable patch.
Use FBI on your hacked 3DS to locate the file, select "Install and delete CIA" for better space management.
If it is a large game or update, ensure you have enough free blocks. To give you a better review, could you clarify:
"EngPatch" indicates a community-translated version, usually for a game that was not released in English in Western territories.