<input name="university" type="text" id="university" value="<? echo $uni_name['name'] ?>">

<input <?php echo empty($uni_name['name']) ? '' : 'readonly' ?> name="university" type="text" id="university" value="<?php echo $uni_name['name'] ?>">

<input name="university" type="text" id="university" value="<?= $uni_name['name'] ?>" <?= $uni_name['name'] ? 'readonly="true"' : '' ?>>