Actually the answer is "NO". We cant upgrade any Linux OS version from one version to different version like from 4x to 5x or 5x to 6x.
I personally tried to install/update package using 6.8 repo on 5.11 servers , but it didnt wrok .
But you can upgrade to any version within perticular version like from 5.1 to you can directly upgrade to 5.x versions like 5.2----5.11) same like for 6x/7x.
Try comment yourself below if any ??????