Hey i want to update my iphone 6s Since i cant activate it

You must have a SIM card in the phone to activate it. If the phone is locked to a carrier it must be a SIM from that carrier, however, it does not have to be a currently active SIM. It can be one that has been deactivated.

You can’t update it if you can’t activate it, so solve the activation problem first. Why can’t you activate it? Have you tried this Apple support article→If you can't activate your iPhone - Apple Support

Who is “they”? And that phone was discontinued either 3 or 5 years ago (depending on storage capacity), so it can’t possibly be new.

But anyway, here are instructions to update it→Update your iPhone, iPad, or iPod touch - Apple Support and here’s a companion video:

I can’t tell anything from that, other than it was a phone probably intended for sale in Europe. But even that isn’t certain.