I’m not sure what you mean by the template var. content, but maybe this will help.
You can get the template variable object with
<?php
$tv = $modx->getObject('modTemplateVar',$id); // $id = ID of the TV itself
// or
$tv = $modx->getObject('modTemplateVar',array('name'=>'MyTV'));
Then these will get various values:
<?php
$v = $tv->getContent(); // for the default value of the TV itself.
$v = $tv->getValue(12); // for the raw value of the TV in doc 12
$v = $tv->getValue($modx->resource->get('id')); // for the raw value of the TV in the current doc.
$v = $tv->renderOutput(12); // for the processed value of the TV in doc 12.
$v = $tv->renderOutput($modx->resource->get('id')); // for the processed value of the TV in the current doc.
