{% for comp in companies %}
    {% for cat in comp.category.all %}
       {{ cat }}
    {% endfor %}
{% endfor %}

#models.py
from django.db import models
from django.contrib.auth.models import User

class UserProfile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    sid = models.CharField(max_length=36)
    ISN = models.IntegerField()

#views.py
def auth(request, k_response = None):
    if request.user.is_authenticated:
        return redirect('../')
    else:
        if request.method == 'POST':
            if k_response is None:
                response = otherAuth(request.POST['Name'],request.POST['Psw'])
            if not response['error']:
                if username_present(request.POST['Name']):
                    print('user exists, login')
                    user = authenticate(username=request.POST['Name'], password=request.POST['Psw'])
                    if user is not None:
                        print('Success auth')
                        user.sid = response['sid']
                        user.ISN = response['ISN']
                        user.save()
                        login(request,user)
                        return redirect('../')
                        # A backend authenticated the credentials
                    else:
                        print('Oops')
                        # No backend authenticated the credentials
                else:
                    print('create user, login')
                    user = User.objects.create_user(request.POST['Name'], 'lol@temp.ru', request.POST['Psw'])
                    user.save()
                    auth(request,response)
            return render(request,'front/login.html',context =
            {
                'error_message':response['error'],
                'message':response['message'],
                'output':response['ISN'] + ' ' +response['sid'],
            })
    return render(request,'front/login.html')