Ross was bought out by Bowtech in 2008 and manufacturing of the Ross line was stopped in 2009 I believe. I am a Bowtech dealer and I know that Ross is not a part of the Pure Archery Group. Finding parts will be tough. Might be able to find a used bow on ebay or Archery Talk classifieds.
You’d be better off investing in a different bow. Like previously stated parts are none existent for those unless you were able to find another used one. But then you’re just purchasing another bow that you can’t get parts for.