var selValue = $('input[name=rbnNumber]:checked').val();
In above code, rbnNumber is name of the radio group.
You can also get the value of individual radio button using it's ID as selector.
var selValue = $('#rbnNumber:checked').val();
If you want to get ID of selected radio button out of group of radio button, then below code will work.
var selValue = $('input[name=rbnNumber]:checked').attr('id');
See Result, jQuery and HTML code below:
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