I took flag's and applied to this code and it works.
Flags Install File - Country Only
1. Create Flags Profile Fields:
Go to AdminCP > Profile Fields > Add new Profile field > Single Select Menu
Title - Country Flag
Description - Select your Country Flag
Options - [copy and paste list of countries in country_flags_list.txt to this option field]
Set Default: None
Editable By User: Yes
Display Page: Edit Profile
Write down your field number, ie field8
2. Edit the postbit_legacy template:
Go to AdminCP > Styles & Templates > Style Manager
In your template list on the right select Edit Templates from the dropdown menu of the desired template
Double click Postbit Templates
Double click postbit_legacy
FIND:
<div>
$vbphrase[posts]: $post[posts]
</div>
BELOW, ADD:
<!-- / flags start -->
<div>
<if condition="$post[fieldX]"><img src="images/flags/$post[fieldX].gif"></if>
</div>
<!-- / flags end -->
Change X to the field id for your country flag.
ie, if your country flag is field8 the code will look like this:
<!-- / flags start -->
<div>
<if condition="$post[field8]"><img src="images/flags/$post[field8].gif"></if>
</div>
<!-- / flags end -->
3. Upload the folder flags to the images directory of your forum.