By Sam Laskaris Writer It’s playoff time for the Six Nations Rivermen. The local Senior B men’s lacrosse squad will kick off its post-season schedule this Friday. The Rivermen will face the Owen Sound North Stars in a best-of-five Ontario Series Lacrosse (OSL) semi-final series. Game one on Friday will be at the Six Nations Sports and Cultural Memorial Centre. The opening faceoff is scheduled for 8 p.m. The North Stars will host Game 2 this Sunday at the Bayshore Community Centre in Owen Sound. And the series will resume with Game 3 in Six Nations on July 26. If necessary, Games 4 and 5, would be staged on July 27 and July 28, in Owen Sound and Six Nations, respectively. The Rivermen will be heavily favoured in their series…