Detect distinction between the model chosen by the user for registration

Question

Hello, so, I created some models to register users in Django 2.0 and now I need to know which one the user chose to register. As you can see I have the individual model (Customusern), legal entity (Customcompany) and the admin model (Customuser), I made a template for the user to choose between these two:

<div class="row">
     <div class="col-4"></div>
     <div class="col-5">
        <h2>Como deseja se cadastrar? </h2>
     </div>
</div>
<br>
<br>
<div class="row">
    <div class="col-3"></div>
    <div class="col-2">
        <a href="{% url 'register' %}"><button type="button" class="btn btn-info btn-lg">Pessoa física   <i class="fas fa-user-alt"></i></button></a>
    </div>
    <div class="col-2"></div>
    <div class="col-2"> <a href="{% url 'registercom' %}"><button type="button" class="btn btn-info btn-lg">Pessoa jurídica   <i class="fas fa-building"></i></button>
    </div>
</div>

And that redirects to these two functions:

def register(request):
    if request.method == 'POST':
        form = CustomUserCreationForm(request.POST or None)
        if form.is_valid():
            user = form.save()
            user.set_password(user.password)
            form.save()
            return render(request, 'register-sucess.html', {'user': user})
    else:
        form = CustomUserCreationForm()
    return render(request, 'register.html', {'form': form})

def registercom(request):
    form = CustomCompanyCreationForm(request.POST or None)
    if form.is_valid():
        user = form.save()
        user.set_password(user.password)
        form.save()
        return render(request, 'register-sucess.html', {'user': user})
    return render(request, 'register.html', {'form': form})

How do I create an algorithm that I can detect this difference, being that they are different models, for example so that I can perform different profile edits with the appropriate fields?

#TODO: MODEL ADMIN E PAI DOS DEMAIS MODELS DE LOGIN
class CustomUser(AbstractBaseUser):
    email = models.EmailField(_('E-mail '), max_length=255, unique=True)
    username = models.CharField(_('Nome de usuário '), max_length=15, unique=True)
    date_joined = models.CharField(_('Data de início '), max_length=20, default=timezone.now())
    is_active = models.BooleanField(default=True)
    is_admin = models.BooleanField(default=False)

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['username']
    objects = UserManager()
    class Meta:
        verbose_name = _('Usuário')
        verbose_name_plural = _('Usuários')
    def __str__(self):
        return self.username
    def has_perm(self, perm, obj=None):
        return True
    def has_module_perms(self, app_label):
        return True
    @property
    def is_staff(self):
        return self.is_admin

#TODO: MODEL DE PESSOA JURÍDICA, SEM VALIDADOR PARA CPNPJ/TELEFONE/CEP
class CustomCompany(CustomUser):
    name = models.CharField(_('Razão social '), max_length= 30, default=' ')
    UF_CHOICES = (
        ('ac','AC'),
        ('al','AL'),
        ('ap','AP'),
        ('am','AM'),
        ('ba','BA'),
        ('ce','CE'),
        ('df','DF'),
        ('es','ES'),
        ('go','GO'),
        ('ma','MA'),
        ('mt','MT'),
        ('ms','MS'),
        ('mg','MG'),
        ('pa','PA'),
        ('pb','PB'),
        ('pr','PR'),
        ('pe','PE'),
        ('pi','PI'),
        ('rj','RJ'),
        ('rn','RN'),
        ('rs','RS'),
        ('ro','RO'),
        ('rr','RR'),
        ('sc','SC'),
        ('sp','SP'),
        ('se','SE'),
        ('to','TO'),

    )
    DEP_CHOICES = (
        ('lab', 'Laboratório Protético'),
        ('clin', 'Clínica Odontológica'),
        ('out', 'Outro tipo'),
    )
    departamento = models.CharField(_('Estabelecimento '), max_length=10, choices=DEP_CHOICES, default='clin')
    cnpj = models.CharField(_('CNPJ(somente números) '), max_length=12, unique=True, default=' ')
    telefone = models.CharField(_('Telefone '), max_length=12, default=' ')
    cep = models.CharField(_('CEP '), max_length=10, default=' ')
    endereco = models.CharField(_('Endereço '), max_length=30, default=' ')
    cidade = models.CharField(_('Cidade '), max_length=20, default=' ')
    uf = models.CharField(_('UF '), max_length=2, choices=UF_CHOICES, default='sp')
    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['name', 'departamento', 'cnpj', 'telefone', 'cep', 'endereco', 'cidade', 'uf']
    class Meta:
        verbose_name = 'Cadastro jurídico'
        verbose_name_plural = "Cadastros jurídicos"

    def create_user(sender, instance, created, **kwargs):
        if created:
            CustomCompany.objects.create(user=instance)

    @receiver(post_save, sender=User)
    def save_user(sender, instance, **kwargs):
        instance.profile.save()

#TODO: MODEL DE PESSOA FÍSICA, SEM VALIDADOR PARA CPF/TELEFONE/CEP
class CustomUserN(CustomUser):
    name = models.CharField(_('Nome completo '), max_length=30, default=' ')
    USER_CHOICES = (
        ('dentista', 'Dentista'),
        ('protetico', 'Protético'),
        ('outra','Outra'),
    )
    UF_CHOICES = (
        ('ac', 'AC'),
        ('al', 'AL'),
        ('ap', 'AP'),
        ('am', 'AM'),
        ('ba', 'BA'),
        ('ce', 'CE'),
        ('df', 'DF'),
        ('es', 'ES'),
        ('go', 'GO'),
        ('ma', 'MA'),
        ('mt', 'MT'),
        ('ms', 'MS'),
        ('mg', 'MG'),
        ('pa', 'PA'),
        ('pb', 'PB'),
        ('pr', 'PR'),
        ('pe', 'PE'),
        ('pi', 'PI'),
        ('rj', 'RJ'),
        ('rn', 'RN'),
        ('rs', 'RS'),
        ('ro', 'RO'),
        ('rr', 'RR'),
        ('sc', 'SC'),
        ('sp', 'SP'),
        ('se', 'SE'),
        ('to', 'TO'),

    )
    tipo = models.CharField(_('Profissão '), max_length=10, choices=USER_CHOICES, default='dentista')
    cpf = models.CharField(_('CPF(somente números) '), max_length=12, unique=True, default=' ')
    cro = models.CharField(_('CRO(somente números) '), max_length=25, unique=True, default=' ')
    Empresa_para_qual_trabalha = models.ForeignKey(
        CustomCompany, on_delete=models.CASCADE, null=True, blank=True
    )
    telefone = models.CharField(_('Telefone '), max_length=12, default=' ')
    foto = models.ImageField(upload_to='fotos_usuarios', null=True, blank=True)
    cep = models.CharField(_('CEP '), max_length=10, default=' ')
    endereco = models.CharField(_('Endereço '), max_length=30, default=' ')
    cidade = models.CharField(_('Cidade '), max_length=20, default=' ')
    uf = models.CharField(_('UF '), max_length=2, choices=UF_CHOICES, default='sp')
    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['name', 'tipo', 'cpf', 'cro', 'Empresa_para_qual_trabalha', 'telefone','foto', 'cep', 'endereco', 'cidade', 'uf']
    class Meta:
        verbose_name = 'Cadastro físico'
        verbose_name_plural = "Cadastros físicos"

    def create_user(sender, instance, created, **kwargs):
        if created:
            CustomUserN.objects.create(user=instance)

    @receiver(post_save, sender=User)
    def save_user(sender, instance, **kwargs):
        instance.profile.save()