You are free to make up names of birthplaces just as long as they aren't actual places in real life.

For example, your character cannot be from Detroit, or New York, or some other known place on Earth. You're also free to pick a pre-existing place on Ramath-lehi where your character has been born, such as Ajita (lots of "higher society" characters live here), Bhim (more middle classed characters and varied criminals live here), etc.