"It is twenty minutes to six."
Translation:Il est six heures moins vingt.
Yes,there are other ways but not the way you specified.
You can also say the following, using the 24hr clock.
Il est cinq heures quarante → It is 5:40 (ie 20 mins to six in the morning) et
Il est dix-sept heures quarante → It is 17:40 (ie 20 mins to six in the late afternoon / evening)
To my knowledge jusqu'à is never used in relation to telling the time.
FYI: This is just information on telling the time, I have no idea if either would be acceptable translations for the given sentence as Duolingo tries, where it is fitting, to stay as close to a literal translation as possible. It is part of the pedagogy the course uses to drill vocabulary.
In the sense of "to", vers generally refers to movement "in the direction of" somewhere. Like the French tongue twister "le vert ver va vers le vert verre" - "the green worm goes towards the green glass".
It isn't used when telling the time though you can use vers, to speak of someone's imminent arrival:
"Il arrivera vers 14 h."
"He's expected to arrive at around 2pm."