There is no chance to underestimate the Manchester United team. They are undoubtedly stronger than Galatasaray. However, Manchester United's performance this season is very weak. Not only are they performing poorly in the Champions League, the team's performance in the Premier League is even worse. Manchester United failed to win against Galatasaray at home. They have lost two out of three matches. They got a narrow 1-0 win against Copenhagen in the last match. I don't think Manchester United will win against Galatasaray with such a poor performance. Galatasaray's players will be confident in the home match. I will say the match will be a draw or Galatasaray will win. I don't consider Manchester United as favourites.
Weaknesses and inconsistency in maintaining their performance in the Champions League and Premier League have made many people doubt Manchester United chances. In material terms, the players that Manchester United has may be superior to Galatasaray, but overall and in terms of team unity, Galatasaray is more solid than Manchester United. Manchester United opened up opportunities after beating Copenhagen, while in other matches Galatasaray had to recognize Bayern Munich's superiority.
Manchester United must manage to collect several more points by winning the remaining matches, including when they meet Galatasaray in the second leg. I'm not sure Manchester United can wipe out all the matches with a win considering their current performance, but nothing is impossible if Manchester United players are able to motivate themselves to bring the team they are playing for through to the next round.
Everyone agrees that Manchester United is one of the big clubs, and has a long history in the European Champions League. However, this is not enough to make United qualify from the group phase to the last 16, Ten Hag squad must work hard to realize their ambitions if they don't want to be thrown into the Europa League if they finish in third place. We have seen that Bruno and his friends were able to overcome Copenhagen in the first leg, and they lost when they met Galatasaray and Munchen. I think the maximum points The Red Devils can get in the remaining three matches is 6, win over Copenhagen and Galatasaray, when they meet Munchen I'm not so sure United will be able to secure full points.
On the other hand, The Reds Devils chances of qualifying really depend on Galatasaray performance in their three matches. Ten Hag has to think carefully about the match ahead, if he makes another wrong move he could lose his job. His quality will be questioned if he fails to get his squad through the group phase, and his credibility will decrease drastically.