JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<div class="col-lg-7">
    <div class="form-group">
        <div class="form-check form-check-inline">
            <input class="form-check-input" type="radio" name="tipouser" value="1" checked>
            <label class="form-check-label" for="inlineRadio1">CNPJ</label>
        </div>
        <div class="form-check form-check-inline">
            <input class="form-check-input" type="radio" name="tipouser" value="2">
            <label class="form-check-label" for="inlineRadio2">CRC</label>
        </div>
    </div>
    <div class="form-group">                                   
        <input type="text" required="required" class="form-control" maxlength="14" name="usuario" id="InputUsuario" pattern="[0-9]+$" placeholder="Usuário">                                    
        <small class="text-muted">Apenas números</small>
   </div>

JavaScript

$(function () {
	var usuario = $('[name="usuario"]');
  var tipouser = $('[name="tipouser"]');
  usuario.attr({placeholder:"Insira seu CNPJ",maxlength:"14"});
	tipouser.change(function () {                    
		if($(this).val() === '1'){
			usuario.attr({placeholder:"Insira seu CNPJ",maxlength:"14"});
		}
		if($(this).val() ==='2'){
			usuario.attr({placeholder:"Insira seu CRC",maxlength:"8"});
		}
	});
});