Your iPad mini 4 is too new for either Snow Leopard, or iTunes 11.
If you need to do updates through iTunes, or a full restore, you will need a newer system, or simply a newer Mac.
Mountain Lion or newer will be good, as that will have iTunes at version 12.3 or later.
If your Mac cannot be updated past Snow Leopard, and you still need to restore your iPad, then you have some decisions to make, I suppose.
1. Replace your Mac with a newer model.
2. Upgrade OS X to at least Mountain Lion (OS X 10.8.5), or newer. If the Mac is too old to accept that update, then you have to decide if upgrading/restoring the iPad is important enough to replace your Mac.