Sometimes people forget the experience of the team that is one of the strengths for Madrid to get good results every season. In Madrid's history we all know how the final result is and in my opinion this season even though Madrid has to experience a little problem with injured players, but just look in January Ancelotti will get new players to advance to the round of 16.
Madrid may end up in the play-off position, but that doesn't mean Madrid can't get into the round of 16.
A lot will change in the next month and we will see teams that currently look strong become worse and teams that look bad will become better.
the certainty in this your statement suggests that you have very limited knowledge of Real Madrid and what they can do even when you least expected them to do it. Real Madrid for a fact haven't been consistent in the UEFA Champions League competition this season and is still struggling to make it to the knockout stages but considering the club's history and the quality of players in the team, I think Real Madrid can still go all the way and win the UEFA Champions League this season.
Real Madrid will reach the round of 16 and might even retain the UEFA Champions League title at the end of the season