I think What Happened to Draco Malfoy by ghostlynimbus might be work you're looking for
It's about Draco being a slave and about to be sold when the Aurors come to arrest them and Ron is there too.
At the beginning of the fic Ron announces that the Aurors have raided a group that were holding slave prostitutes.
“Raid today. Illegal brothel.” Ron says eventually. “We found…”
He has to stop to clear his throat, and Hermione leans into his side in a comforting gesture.
“We found a lot of trafficked omegas.”
And then while the other slaves have been taken home by their family Draco still stays at the Mungo's. Ron comes to the Grimmauld Place and tells Harry about this, who decides to take Draco home with him.
Most of the rescued slaves are sent to their families, but since Draco's dad is a criminal and his mother is an omega, Draco can't be released into either of their cares.
“Some… some of them are going to have to stay at St. Mungo’s.” Ron continues, eventually. “And there are some we still have to sort out bond wise.”
There would have to be trials, to determine the legal validity of any bonds any of the omegas were still under, but with a case like this the trials should be over quickly with the Ministry ruling them invalid and sending the omegas home to their families.
“But there’s one, even… even if his trial goes the way it should and his previous bond is deemed invalid, we’ve got nowhere to send him.” Ron says. “He only has one alpha relative, and he’s a known criminal so the ministry can’t release custody of an omega to him.”
“It’s.. it’s Malfoy.” Ron says.
“I’ll do it.” Harry says quietly, rushing into something he isn’t sure he can actually handle. He clears his throat and says again, louder. “I’ll take him.”
And the next forward is about Harry helping him to be better.
Over many chapters Harry tries to help Draco become more comfortable and deal with his trauma. He tries to provide Draco with safe spaces, respects Draco's boundaries, gets books that Draco likes, etc.. This is the majority of the fic. By the end Harry, Draco, and Delilah (their child) are a mostly happy family:
Draco still has bad moments.
Times when the fear and the pain of his past overwhelms him. Times when it feels like he’s still broken, like he’ll never be fixed. Times when he’s still scared and distrustful of any alpha, even the ones he knows wont hurt him.
But those times pass.
Harry helps bring him back, or Delilah.
Draco wipes his face with the hand not hiding the present behind his back, and is only mildly surprised to find there are tears on his cheeks.
“I’m okay.” Draco says, reassuring his mate. “Just happy.”
I may have confused the following with another story, but I remember Ron and Hermione being married with two children and coming to see Harry and Draco for dinner, with Draco still being on guard?
Ron and Hermione do come for dinner, and Draco is uncomfortable the whole time.
When Ron and Hermione arrive through the floo though, it’s back to staring at the floor and taking up as little space as possible. Harry greets his friends with familiarity and warm hugs, and Draco stands back in silence. Harry doesn’t miss the way Draco leans ever so slightly closer to him afterwards, though he doesn’t know what it means.
If there's mention of the two having children, I missed it.