If your version of nuke does not have the version number in the footer then use this tutorial to see what the version you are using. .

Steps :
If you have access to phpmyadmin use part 1 of this tutorial, otherwise skip this part.

Part 1
This is only for those that have phpmyadmin installed on their hosting. Your host in most cases can tell you how to access it.Visit phpmyadmin and select the name of your nuke database( see fig1).

fig1.

You will now see a list of all the tables in your database. The one you are looking for is nuke_config (the nuke_ part may be different if you used a different prefix when installing phpnuke) (see fig2) .

fig2.

Click on the nuke_config table to list all the fields. At the top of phpmyadmin click Browse (see fig3)

fig4.

Scroll horizontally until you see Version_Num.

Part 2
This part is only for those that do not have access to phpmyadmin or want an easier way to check the version number. Create an empty php file and name it anything like nukeversion.php. Paste the following codes inside it.

<?
//CREATED BY WESTERN STUDIOS

require_once("mainfile.php");
global $prefix, $db;

$result = $db->sql_query("select Version_Num from $prefix"._config."");
while(list($Version) = $db->sql_fetchrow($result)) {

echo "<br><br><center>My Nuke version is <b>$Version</b></center>";
}
?>

Save your php file and upload to your main nuke root directory where config.php and mainfile.php are located. Point to your file in your browser like the following..

http://www.yoursite.com/html/nukeversion.php.

That's All!! Visit the forums for more help.