Is it possible to download rpm files from this k3b page for an offline installation? When I try to install k3b-1.0.5-0.pm.6.x86_64.rpm or lang-1.0.5-0.pm.6.x86_64.rpm the system says that they depend on each other 
Go with --nodeps switch… As far as i know… It wont be a proble using nodeps… Unless there is no other dependencies
Mutual dependency is not a problem, just install both in one go:
rpm -i package1.rpm package2.rpm
or whatever the equivalent is with repo tools on top of rpm.
Thanks for answers!
Both methods worked for me.
But it’s better to solve it without using --nodeps because that could cause other dependencies to be ignored.