So...what are the chances if I bought a brand new ipad that it would have something older than 6.1.2 on it?
Literally 0 in a retail store.
Your only hope is to buy an unopened one from months ago off someone.
Depends on the store/location - Do your research and find a store in a quiet location. Then ask the retailer to look in their system and find the oldest batch (stock is batched according to date received). I'm sure they will be happy to clear out older stock. Goodluck.
So...what are the chances if I bought a brand new ipad that it would have something older than 6.1.2 on it?
Why does it matter? If it came with something older, just upgrade yourself. Or do you actually WANT an older version?