1) Django 1.6 is an unsupported Django version https://www.djangoproject.com/download/#supported-versions
you can see that Django 1.6 was supported until April 2015. So try to migrate to 1.8 LTS or 1.9 now and have migrations in your Django project or integrate South in your old Django app to have migrations http://south.readthedocs.org/en/latest/index.html
2) No there is not a quicker function in Django 1.6 (django-admin/manage.py command) that drop all tables. The more closer thing in this old versions is:
manage.py sqlclear appname
and put the output in your sql shell, maybe can work with pipe.
manage py sqlclear appname | manage.py dbshell
at least with MySQL works well.