In my Django app, a specific user input will result in the creation of a new model. Here is the code I am using to create the model and register it.
model = type
Subprocess can migrate your model using migrate command. So try this it will work
import subprocess
command = 'python manage.py migrate'
proc = subprocess.Popen(command, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
stdout, stderr = proc.communicate(command)
Read also this https://code.djangoproject.com/wiki/DynamicModels If it can help for create dynamic model