JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css">
<link rel="stylesheet" href="https://silviomoreto.github.io/bootstrap-select/dist/css/bootstrap-select.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<script src="https://silviomoreto.github.io/bootstrap-select/dist/js/bootstrap-select.min.js"></script>
<div class="form-group "><label class="col-sm-3 control-label" for="examCity1">Choice of Country</label>    <div class="col-sm-9 controls">
<div class="btn-group bootstrap-select form-control"><button type="button" class="btn dropdown-toggle btn-default" data-toggle="dropdown" data-id="examCity1" title="Select Exam City 1"><span class="filter-option pull-left">Select Exam City 1</span>&nbsp;<span class="bs-caret"><span class="caret"></span></span></button><div class="dropdown-menu open"><div class="bs-searchbox"><input type="text" class="form-control" autocomplete="off"></div><ul class="dropdown-menu inner" role="menu"><li data-original-index="0" class="selected"><a tabindex="0" class="" style="" data-tokens="null"><span class="text">Select Exam City 1</span><span class="glyphicon glyphicon-ok check-mark"></span></a></li></ul></div><select name="examCity1" id="examCity1" class="form-control" data-size="20" data-live-search="true" tabindex="-98">
    <option value="-1">Select Exam City 1</option>


</select></div>

</div>
</div>

JavaScript

$(document).ready(function(){

var data = {"examCities1":{"1":"Australia","2":"Bangladesh","32":"Brazil","4":"England","5":"India","6":"UAE"}};
console.log(data.examCities1);
loadJSONtoSelectBox('#examCity1', data.examCities1);

});


function loadJSONtoSelectBox(selector, options)
{

   $(selector).selectpicker();
   $.each(options, function(key, value) {
       $('<option data-tokens="'+value+'" value="' + key + '">' + value + '</option>').appendTo(selector);
       $(selector).focus();
  });

  $(selector).selectpicker('refresh');
}