PSG, who face already qualified Dortmund (10 points) in their last Champions League Group F game tonight, are currently second on the group table with 7 points.
PSG will top the group if the beat BVB. They can still qualify for round of 16 as group runners-up with a draw.
For PSG to qualify as runners-up they need to avoid defeat and Newcastle don't win against Milan.
A Newcastle and Milan draw, who are both on 5 points each, will also send PSG (on 7 points currently) to the next round of UCL.
A PSG defeat against BVB will send them to Europa League considering Milan vs Newcastle ends up in a winner, getting to 8 points against PSG's 7 points.