Using liquid markup, a macro can give different responses based on the content of your ticket.

Ticket tags

The placeholder {{ticket.tags}}  lists the ticket tags as a string with each tag separated by a space. The following macro will give a different response based on the tags on the ticket.

{% assign myTags = ticket.tags | split: ' ' %}

{% for tag in myTags%}

{% case {tag} %}

{% when 'tag1' %}

You have tag1

{% when 'tag2' %}

You have tag2

{% endcase %}

{% endfor %}

Custom Fields

 To base macros on custom ticket fields, first find its field ID from Admin>Ticket Fields.

Your macro can then say:

{% case ticket.ticket_field_360000034029%}

{% when 'My Value' %}

Your selected My Value

{% when 'My Value2' %}

Your selected My Value2

{% endcase %}

 ...as long as your replace 360000034029 with the ticket ID of your custom field. 

If using a drop-down field, use the tag values for each option.

Note that the values in the case statement are case sensitive.

You can find out more on custom field placeholders here.