Depends on where you ordered from. I got a 6S+ 16 GB about two weeks ago at the Apple Store (in Albuquerque NM, while I was there for the weekend). It had 9.0.2. Sadly, I found I needed more space, so ended up returning it, and got a 64GB from a seller on Swappa, but it turned out the device had no warranty, so I ended up returning it (no warranty meant any repairs would cost me, or whatever).
Got a 64GB AT&T 6+ yesterday at Best Buy and it had 9.1 - got home, jail broke it, and it went into a boot loop. Tried for hours, and various methods to get it out, with zero luck. So -- the ones with older versions of iOS are out there, its just a matter of what size/color and carrier you ordered, and from where.