JSFiddle - React, Tailwind, and code Playground
HTML
<div class="form-group">
<label class="col-sm-5 control-label">Check either YES or NO</label>
<div class="col-sm-7">
<div class="radio radiobtnBox">
<input name="data[User][certificate]" value="Y" class="radio1" required="required" aria-required="true" autocomplete="off" type="radio"><span>Yes</span>
<input name="data[User][certificate]" value="N" class="radio1" required="required" aria-required="true" autocomplete="false" type="radio"><span>No</span>
<div aria-required="true">
<textarea class="form-control radio_check" cols="30" rows="6" required="required" aria-required="true" style="display: block;"></textarea>
</div>
</div>
</div>
CSS
textarea{border:2px solid #333;width:340px;border-radius:5px;margin-top:10px;}
JavaScript
$(".radio_check").hide();
$(".radio1 ").click(function(){
if($(this).attr("value")=="Y"){
$(".radio_check").css("display","block");
}
else{
$(".radio_check").hide();
}
});