JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.11.0/jquery.validate.min.js"></script>
<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.11.0/additional-methods.js"></script>
<form id="myform">
    <select name="t_dropdown" id="t_dropdown" class="form-control required">
                    <option value="">Select Value</option>
                    <option value="1">1</option>
                    <option value="2">2</option>
                    <option value="3">3</option>
                    <option value="4">4</option>
                    <option value="5">5</option>
                    </select>

                    <select name="p_dropdown" id="p_dropdown" class="form-control required">
                    <option value="">Select Value</option>
                    <option value="1">1</option>
                    <option value="2">2</option>
                    <option value="3">3</option>
                    <option value="4">4</option>
                    <option value="5">5</option>
                    <option value="6">6</option>
                    <option value=">6">>6</option>
                    </select>
    <input type="submit" />
</form>
<a id="docs" href="http://docs.jquery.com/Plugins/Validation" target="_blank">Validation Documentation</a>

CSS

#docs {
    display: block;
    position: fixed;
    bottom: 0;
    right: 0;
}

JavaScript

$(document).ready(function () {

    $.validator.addMethod("matchValue", function (value, element) {
       if($('#t_dropdown').val()==4)
       {
           return value < 4;
       }
        else
        {
            return true;
        }

    }, 'Invalid Value');

    $('#myform').validate({ // initialize the plugin
        rules: {
            p_dropdown: {
                matchValue: true
            }
        },
        submitHandler: function (form) { // for demo
            alert('valid form submitted'); // for demo
            return false; // for demo
        }
    });

});