JSFiddle - React, Tailwind, and code Playground
HTML
<select id="selecionados[]" name="selecionados[]" size="20" multiple>
<option value="A">A</option>
<option value="B">B</option>
</select>
JavaScript
var selectID = $('#selecionados\\[\\]');
console.log(selectID);
var selectNome = $('select[name=selecionados\\[\\]]');
console.log(selectID);