As far as I know the gold version of the j3 (2016) doesn't have marshmallow otherwise many of us are waiting for 7.1.1 to release especially with the 2017 j3 about to release if it hasn't already
The j3 has been unmentioned by Samsung as they plan to update the j5 and j7 along with other devices. Each color of device has a different model number though. There are also other things That help seperate models from each other. I do not even know if the white and gold models have 6.0.1 marshmallow, which if they run 5.1.1 lollipop then the chances of getting 7.1.1 nougat are unlikely to not at all. There has been a release of the j3 (2017) which is planned to run nougat in February. Another factor is if your carrier pushes an update out for your device, if samsung chooses to update the j3 (2016) As far as I am concerned, anything is possible.