Getting index of item in items inside twig template If I use any loop in Drupal, I can get loop.index to get the index of looped item. - Ref#1

For example -

    {% for tag in content.some_array %}
      &lt;div class="item-count-{{loop.index}}"&gt;{{ tag.content }}&lt;/div&gt;
    {% endfor %}


This is a field containing paragraph type -

field--field-container.html.twig

and its content is {{items}} ({{items|length}} gives the desired count)

The above template iterate through it's items and include the following template multiple times-
paragraph--multiple-blocks.html.twig
and its html is

    &lt;div class="multiple-blocks multiple-block-count-{{loop.index}}"&gt;
    =====CONTENT=====
    &lt;/div&gt;


But I cannot get the loop.index (Ref#1) in the paragraph--multiple-blocks.html.twig template. I tried (surely google search shows all links visited) kint() debugging but could not get anything related to the count or index of the item iterated.

I will be grateful to any guide/help (don't want to code in PHP) close to get this done in twig files will.
You can't, because the loop index is local. And you don't need a class with the index in the paragraph when you have it in the surrounding div for targeting it in CSS.

There is also a fundamental aspect with rendering referenced entities. They are cached and not necessarily rebuild when the order in the field changes. This is even more problematic for other entities than paragraphs, which can be used in more than one place in different orders.