In Logan, We see this character talk to someone over the radio towards the end of the film.
Who is Rictor talking to?
We never find out who the escapees were speaking to. All we know is that the adults that got them out of Transigen had gotten in contact with a place in Canada were the mutant children would be given asylum. Rictor was speaking to someone from that group, relaying their status and making plans to leave their temporary safehouse and go north. As far as I remember, no one ever gives any details about who that group is; Gabriela only ever refers to the meeting spot by coordinates.
If there are any more movies set in that universe we may find out who that group is, but given the ending, I wouldn't necessarily count on it.
In the recently released screenplay for Logan the dialog between Rictor and the people over the radio is this:
RICTOR: ...We're leaving tomorrow at dawn. We're going to cross the border.
LOGAN: To Canada?
(walking off) Si.
Logan finds Laura and the other mutant children packing up belongings. The older ones lead younger ones-- loading guns, stocking ammo, prepared for anything.
Rictor is hunched over a short wave radio. There are voices. In French. He clicks off, crosses to the railing, addresses the others like an adolescent general:
RICTOR: That was the signal. They're ready for us on the other side.
Unfortunately, it's unclear and unstated exactly who or what the voices are across the border in Canada though.
It could be a surviving adult mutant whose part of a small group leading the mutant children to the other side, Canada, where they can hopefully form a new X-Men force or "X-Force"! This may just be my theory, but it makes more sense and far more logical than what may be planned for the sequel to "Logan"!
I'm hoping it's a small group who survived the events of what happened at Westchester or Professor X's school, like maybe Rogue or Kitty Pryde or someone who was once a student and is now an adult or someone Professor Charles Xavier trusted and knew to trust should something threaten Mutant-kind!
Rictor was talking to Aurora from Canada's superhero mutant team Alpha Flight. She is a Canadian-French speaker.
Logan is also Canadian and was a former member of Alpha Flight before he joined the X-Men.