Q: Transfer data from my old iPhone to my current iPhone

Sorry if you restore from your iphone 6 backup, it will wipe all data off your 6s.

What data are you trying to transfer?

Then you will need to decide what data is more important to you the current information or the backup of your 6.

Khatab678 wrote:

 

I Need both of the data I don't want to delete anything, is it possible to merge two backups to one then I restore to the iPhone 6s?.

No its not possible to merge two backups to one, otherwise I would've stated that in my original response to you.

You can import pics from your 6 to your computer Import photos and videos from your iPhone, iPad, or iPod touch to your computer - Apple Support  then sync it back to your 6s Sync photos from your computer to your iOS device using iTunes - Apple Support

As stated you'll need to decide what data is more important and move on from there.

Good luck.

You're welcome.