The apartment community is mobile ~ it is said that telecom lines are not allowed to come in ~ but our room has telephone lines ~ can we take the telecom network?

The telephone line in the room only means that you can answer the phone. The key depends on whether the telecommunications company has set up a junction box in your community and whether it can successfully connect your telephone line. Judging from your description, it is estimated that the community didn't let telecom companies set up communication cables in the community at all, so don't expect to use telecom broadband.