What phone do you have sir? Samsung and other manufacturers are crappy with their software updates - If a new android version comes up, it takes months before the manufacturer approves it on certain devices, or they just never update old phones.
Ive checked online and according to others and the Samsung firmware website, Nougat updates were recently rolled out, but it would update by country. Wait atleast a month or less and keep checking the Software Update tab in the Settings.
