Restore ipad from 6.1.2 to 9.1 (but not higher). How to do it?

Question

iOS

I wanted to move to a new 9.1 system and jailbreak it with panga.
When restoring via shift, it says that the device is not qualified for this software.
I read when downloading ispw, about some signed and unsigned firmware.
Clarify please.

Answer 1

I understand - no way.
The firmware is signed for each device, and Apple only returns the signature for the latest firmware on your device when you try to restore it. Installing the old version without fraud with these signatures will not work. For the shenanigans to work, you must have signatures for Apple's 9.1, which you most likely don't have and now never will.

Answer 2

The answer above is absolutely correct.