It will be tough for Real Madrid to get one of the eight automatic qualification slots for the UCL rounds of sixteen. It will solely be determined by the outcome of the games by other clubs who are on top of Los Blancos on the table. But they can secure it if they win the remaining two games between them and Salzburg and Stade Brest 29. If they are lucky enough, they might make it, if not they would have to go through another qualification round. Real have a good team but the three losses lately in the competition due to injured players really hampered the progress of the club.
What Madrid needs to do is maximize the two remaining games and then hope for some luck from the games above them that will end badly. The result can only be hoped for like that.
Even if they have to go through the Playoffs, I think Madrid will be one of the teams that will be favored to qualify for the knockout round. It's just that after the knockout round starts of course it will require their hard work and must be more focused because their chance is to face the team that is currently in the top 8. The current Champions League system allows big teams to beat each other at the beginning.