[Answered ]-How can I use tag set in Django(jinja)?

Yes you can use {% set %} to create variable to store data in Jinja but django uses it’s own template engine not Jinja but if you want to use Jinja then you can change default Template Engine to create variable in django use {% with %}
for addition use add

{% with  Ne_page=page_data.current_page|add:"+1" %}
{% endwith %}

{% with  Pr_page=page_data.current_page|add:"-1" %}
{% endwith %}

Note : you’ve to use your variable in between with endwith block
eg.

{% with alpha=1 %}
   {{alpha}} use it inside block
{% endwith %}