iPhone 6s update please come

To update to the most recent, compatible version of iOS 15.7.5, please see: Update your iPhone, iPad, or iPod touch - Apple Support

And: If your iPhone, iPad, or iPod touch won't update - Apple Support

If the above Apple articles do not help, please post back with relevant information. 

Mohsinalimazari wrote:

iPhone 6s

Can we assume you have already solved your tech support issue by merely posting the text above?