Solution:
You can use PHP variable in JQuery/Javascript easily check below steps
1) Stored PHP variable value in HTML input tag as type hidden
<input type="hidden" value="<?php echo $phpvariabletext;?>" id="phpvariable">
2) After assign variable value in HTML input tag. You can get value in JQuery/Javascript.
<script type="text/javascript">
var content = $('#phpvariable').val();
var newmodal = new tingle.modal();
function openmodal() {
newmodal.open();
newmodal.setContent(content);
}
</script>