Can we give serial numbers in views to each columns or row in a sequential manner?
When format is content

You can override views-view-unformatted.html.twig and perhaps create a twig file for just this particular view.  

If your view name is test you can copy from core/modules/views/templates/views-view-unformatted.html.twig to your THEMENAME/templates folder and rename to views-view-unformatted--test.html.twig.  In this twig file you can use {{loop.index}} inside the for loop to give you the row index/count sort of like this:

{% if title %}
  &lt;h3&gt;{{ title }}&lt;/h3&gt;
{% endif %}
{% for row in rows %}
  {%
    set row_classes = [
      default_row_class ? 'views-row',
    ]
  %}
  &lt;div{{ row.attributes.addClass(row_classes) }}&gt;
    &lt;span&gt;row count: {{loop.index}}&lt;/span&gt;    
    {{ row.content }}
  &lt;/div&gt;
{% endfor %}


When format is fields

Yes you can add view results counter when the format is fields