Macossierra10126frenchiso — _best_

If you see a website offering “macOS Sierra ISO,” it’s almost certainly pirated, fake, or modified.

files via the App Store), you can find archived versions or create one yourself: Archive Sources : Community repositories like Internet Archive macossierra10126frenchiso

If your hardware supports it, you can upgrade from macOS 10.12.6 to newer versions: If you see a website offering “macOS Sierra

: Allocate a minimum of 25–30GB for the installation. ” it’s almost certainly pirated

macOS Sierra requires at least a late 2009 iMac/MacBook or a 2010 MacBook Air/Pro/Mac mini.