The iPhone 6s does not have optical image stabilization. Only the iPhone 6 Plus and 6s Plus feature OIS. However, this is the only difference between the iPhone 6s and 6s Plus cameras. Both 6s devices feature a 12-megapixel iSight camera with Live Photos and 4K video. You can learn more about the iPhone 6s camera here and iPhone 6s Plus camera here.
Does the iPhone 6s have Optical Image Stabilization (OIS)?