For starters the iPhone 6s will be delivered on time which is set for the 25th of September. However picking the rose gold option will see your order delayed for about 2-3 weeks for T-Mobile, but the other carriers seem to be unaffected, so that’s worth taking into consideration as well.
Now if you’d much prefer the larger 5.5-inch iPhone 6s Plus, it seems that the delay is longer. It does not matter which color option you go for, or which carrier you choose, Apple’s shipping estimates for the larger iPhone is now set at 3-4 weeks. Of course if you had pre-ordered it when it first went live you might have gotten it on the 25th of September.
For those slow on the trigger, you’d be out of luck. Given the the popularity of the iPhone, we can only imagine that shipping will continue to delay over the next couple of weeks/months, so if you’d rather not be kept waiting too long, you might want to pre-order the device now.