Question on template render

[AjaxFB]

Django version 3.0.2

j = {{'a': '1', 'b': '2', 'c': '3'}}

when

return render(request,"index.html",{'json':j})

{% for item in json %}
    {% for column in item %}
        {{ item.column }}
    {% endfor %}
{% endfor %}

Why render template cant find/print item.column content?
I need really change this in views.py?