😕
If you knew, then why are you asking? The OTA page has been disabled to even bring up the option of an update. You'll know immediately when an update is available when it's posted. It's already been confirmed however that 6.1.3 breaks your jailbreak anyways, so you'll want to stay away from updating. I'm getting the vibe that you'd "accidentally" update to the latest FW and lose your jailbreak.