This page explains where to buy Final Fantasy VI legitimately.
Super NES Classic
The SNES Classic includes Final Fantasy 3/6.
iOS and Android
A mobile-optimized port of Final Fantasy VI, with revamped graphics, is available on iOS and Android devices. Use the links below to download the app to your device.
A port of Final Fantasy VI, with revamped graphics, is available from Steam for Windows users.
Wii Virtual Console
The original SNES version of Final Fantasy 3/6 is available from the Wii Virtual Console. If you want to get the game on a Wii U, you have to choose Wii Menu to run the Wii U in Wii mode.
Then, in Wii mode (not Wii U mode), run Wii Shop Channel, choose Virtual Console, and search for Final Fantasy III to find the game.
A port of the game was released for PlayStation. This version is also available on Final Fantasy Anthology for PlayStation, which also includes Final Fantasy V.
Game Boy Advance
A Game Boy Advance port was released in 2007. The graphics are unchanged from the SNES version. Some bugs from the SNES version are fixed in the GBA version, and there is some additional gameplay, including a new dungeon. This version is somewhat rare, but might be available on eBay, Amazon, and in used game stores. Beware of fraudulent copies.
The original SNES version of the game is also rare, but might also be available on eBay, Amazon, and in used game stores. Again, beware of fraudulent copies.