<form>
<fieldset id="grup1">
<input type="radio" value="value1" name="grup1">
<input type="radio" value="value2" name="grup1">
</fieldset>
<fieldset id="grup2">
<input type="radio" value="value1" name="grup2">
<input type="radio" value="value2" name="grup2">
<input type="radio" value="value3" name="grup2">
</fieldset>
</form>