Hi namthanh !
teline using javascript code in ja.script.js file to create tabs for modules. you only need assign modules to ja-tab1 and ja-tab2 position , those modules will display on tabs with ja-tab1 position at the top tab and ja–tab2 at the bottom tab.
Please open index.php file in templates/ja_teline folder, go to about line 205 :
<div id="ja-tabswrap" class="clearfix">
<?php if ( $this->countModules('ja-tab1')) { ?>
<ul class="ja-tab-top">
<jdoc:include type="modules" name="ja-tab1" style="jatab" />
</ul>
<?php } ?>
<div class="ja-tab-contentwrap<?php echo $tabstyle;?>"><div id="ja-tab-content"> </div></div>
<?php if ( $this->countModules('ja-tab2')) { ?>
<ul class="ja-tab-bottom">
<jdoc:include type="modules" name="ja-tab2" style="jatab" />
</ul>
<?php } ?>
</div>
this is code for load tabs.