class Service(models.Model):
    name = models.CharField(max_length=255, blank=True, null=True)
    class Meta:
        managed = True
        db_table = 'Service'

class Room(models.Model):
    name = models.CharField(max_length=255, blank=True, null=True)
    service = models.ForeignKey(Service, models.DO_NOTHING, blank=True,
    null=True)
    class Meta:
        managed = True
        db_table = 'Room'

class ServiceSerializer(serializers.ModelSerializer):
    room_set = RoomSerializer(many=True, read_only=True)
    class Meta:
       model = Service
       fields = ('name','room_set')
class RoomSerializer(serializers.ModelSerializer):
    class Meta:
        model = Room
        fields = '__all__'

queryset = Service.objects.filter(room__id=1)
serializer = ServiceSerializer(queryset, many=True)
return JsonResponse(serializer.data, safe=False)

{
     "name": "Hotel1",
     "room_set": [
     {
           "id": 1,
           "name": "Room1"
      },

{
     "name": "Hotel1",
     "room_set": [
     {
           "id": 1,
           "name": "Room1",
      },
      {
            "id": 2,
            "name": "Room2",
      },
      {
             "id": 3,
             "name": "Room3",
      }
  }