JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="//cdn.jsdelivr.net/select2/3.5.2/select2.css">
<script src="//cdn.jsdelivr.net/select2/3.5.2/select2.min.js"></script>
<table width="100%">
    <tbody>
        <tr>
            <th>Flavor Brand</th>
            <th>Flavor Name</th>
            <th>Dropper type</th>
            <th>Quantity Unit</th>
            <th>Quantity</th>
            <th>Add/Remove row</th>
        </tr>
        <tr class="flavors">
            <td>[brand_list]</td>
            <td>
                <select id="arome0" class="select2-select"></select>
            </td>
            <td>
                <select id="dropper0" class="select2-select">
                    <option selected="selected" value="type1">type 1</option>
                    <option value="type2">type 2-3</option>
                </select>
            </td>
            <td>
                <select id="qtyunit0" class="select2-select">
                    <option value="ml">ml</option>
                    <option value="drops">drops</option>
                    <option selected="selected" value="perc">%</option>
                </select>
            </td>
            <td>
                <input id="quantity0" class="quantity" type="number" />
            </td>
            <td>
                <button type="button" class="addline">Add Line</button>
                <button type="button" class="remline">Remove Line</button>
            </td>
        </tr>
    </tbody>
</table>

JavaScript

$(document).on('click', '.addline', function () {
    var $tr = $(this).closest('tr');
    var $lastTr = $tr.closest('table').find('tr:last');

    $lastTr.find('.select2-select').select2('destroy');

    var $clone = $lastTr.clone();

    $clone.find('td').each(function() {
        var el = $(this).find(':first-child');
        var id = el.attr('id') || null;
        if (id) {
            var i = id.substr(id.length - 1);
            var prefix = id.substr(0, (id.length - 1));
            el.attr('id', prefix + (+i + 1));
            el.attr('name', prefix + (+i + 1));
        }
    });
    $tr.closest('tbody').append($clone);
        $lastTr.find('.select2-select').select2();
    $clone.find('.select2-select').select2();
});
$('.select2-select').select2();