The Beocentre 6-26 comes with two powerlink sockets as standard
If you have the optional DSM installed then you have five (5) powerlink connectors 2 X for front 2 x for rear and one for Subwoofer speaker.
So, if you want external Powerlink speakers in the same room, then no problem.
If you want to have a Beolink Active or Beolink Passive in another room then this would be connected to the Masterlink of the Beocentre 6-26