A patch is a modification file that updates the game's data, in this case, the teams, to reflect changes that have occurred since the game's release.
You're looking for a patch to update the teams in FIFA 12 to the 2017 season. Here's some helpful information:
Do you have any specific questions about FIFA 12 patches or installation?
There are several patches available online that claim to update the teams in FIFA 12 to the 2017 season. These patches usually include updated team rosters, kits, and sometimes even new player faces.