Sorting a SortedMap by object attribute

Good afternoon fellow programmers on duty. I'm developing an application that creates from a formary through the information contained in a tabulato.txt file. I was able to develop all the routine of creation of the formulary, now I must order it, according to the attribute "geopolitical" (neighborhoods). Here is the code:

MAP CREATION CLASS:

    package classes.repository;
    import java.io.BufferedReader;
    import java.io.File;
    import java.io.FileReader;
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.LinkedHashMap;
    import java.util.List;
    import java.util.Map;
    import java.util.SortedMap;
    import java.util.TreeMap;
    import classes.model.Clientes;
    import classes.model.Comodatos;
    import classes.model.Zonas;

            public class Tables {
        public SortedMap<String, Clientes> clientes = new TreeMap<>();
public List<Zonas> zonas = new ArrayList<>();
public Map<String, Comodatos> comodatos = new LinkedHashMap<>();

public void tables() {
    try {
        File file = new File("table.txt");
        FileReader fReader = new FileReader(file);
        BufferedReader bReader = new BufferedReader(fReader);
        String leitor = bReader.readLine();
        while ((leitor = bReader.readLine()) != null) {
            String[] leitorSplit = leitor.split("\t");
            clientes.put(leitorSplit[0], new Clientes(leitorSplit)); // leitorSplit[0] == cód do cliente não pode se repetir, por isso utilizei o Map
            comodatos.put(leitorSplit[5], (new Comodatos(leitorSplit)));
        }
        File file = new File("zonasbairros.txt");
        FileReader fReader = new FileReader(file);
        BufferedReader bReader = new BufferedReader(fReader);
        String leitor;
        while ((leitor = bReader.readLine()) != null) {
            String[] leitorSplit = leitor.split("\t");
            zonas.add(new Zonas(leitorSplit));
        }
        bReader.close();
    } catch (IOException e) {
        e.getMessage();
    }
}

}

I implemented a comparable object class to see if it worked, but it did not work:

    package classes.model;
    public class Clientes implements Comparable<Clientes> {

private String cod, fantasia, razaoSocial, endereco, geopolitico, documento, codproduto, descricao, qtd;
private String[] linha;

public Clientes() {
}

public Clientes(String[] linha) {
    this.cod = linha[0];
    this.fantasia = linha[1];
    this.razaoSocial = linha[2];
    this.endereco = linha[3];
    this.geopolitico = linha[4];
}


public String getCod() {
    return cod;
}

public void setCod(String cod) {
    this.cod = cod;
}

// Getters...Setters..

@Override
public int compareTo(Clientes o) {
    return geopolitico.compareTo(o.geopolitico);
}

}

You can easily organize with Collections.sort if you use a List, however the data in the .txt file is repeated and therefore the Map choice. Several heads think better than one. Any light ?? hug!