new iphone 13 connection problems to iphone 6

See this article on how to transfer data.

Use Quick Start to transfer data to a new iPhone or iPad – Apple Support (UK)

PeteSlack wrote:

Unable to pair with my iPhone 6 from iPhone 13

That is correct, you can't pair two Apple devices via bluetooth unless you're tethering.

What exactly are you trying to accomplish?

PeteSlack wrote:

Just transfer data from my iPhone 6 to my new iPhone 13 by the way what’s tethering?

Tethering = hotpsot.

If this doesn't work Use Quick Start to transfer data to a new iPhone or iPad - Apple Support then use your icloud or itunes backup to transfer data.