Facing wi-fi connectivity problem in my 6S after upgrading to iOS 9.2.1. Is this a software or hardware peoblem?

Hello Amit Sarker,

Thanks for using Apple Support Communities.

It's not too clear to me what sort of issue you're having with the Wi-Fi connection on your iPhone, but for general troubleshooting for Wi-Fi issues please follow through the steps outlined in the support article below.

If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network

Cheers.

Hi

Turn your router off for 30 seconds .

When its back on go to settings on iPhone reset network settings .

After reset enter your router wireless key .

Cheers

Brian

Hi

If your router is more than 18 months old ask your network provider for a replacement

Also go to the website for your make of router check for a firmware update .

I buy my own router top of range Netgear R6300 some routers that you isp gives you are not very good .

My router works a the top of a 30 foot garden .

Cheers

Brian