The "21" in WinRa1n's name refers to version 2.1, the latest stable release. It's designed to be the most accessible way for Windows users to jailbreak their devices, requiring no technical knowledge or command-line input.
Lower your expectations. There is no "WinRa1n 21" for iPhone 12 on iOS 17.0. Do not believe YouTube thumbnails showing an iPhone 14 with Cydia—they are fake. The A12+ jailbreak for iOS 17 likely doesn't exist and may never exist due to Apple's Hardened Runtime. winra1n 21 jailbreak ios 17x support top
Follow these steps precisely, paying close attention to the DFU mode entry. The "21" in WinRa1n's name refers to version 2