şekilde denermisiniz o alanı
<?php if(get_template_part( 'kategori' )):?>
 <li class="col-md-3 col-sm-4 col-xs-6">
                        <?php
      get_template_part( 'kategori' ); ?>
      </li>
<?php endif;?>
yada

<?php if(!empty(get_template_part( 'kategori' ))):?>
 <li class="col-md-3 col-sm-4 col-xs-6">
                        <?php
      get_template_part( 'kategori' ); ?>
      </li>
<?php endif;?>