<div class="form-row">
    <div class="form-group col-12 col-md-6">
       [text* text-310 class:form-control placeholder "NOMBRE *"]
    </div>
    <div class="form-group col-12 col-md-6">
      [text text-311 class:form-control placeholder "APELLIDO"]
    </div>
</div>
<div class="form-row">
    <div class="form-group col-12 col-md-6">
      [email* email-237 class:form-control placeholder "EMAIL *"]
    </div>
    <div class="form-group col-12 col-md-6">
      [tel tel-232 class:form-control placeholder "TELÉFONO"]
    </div>
</div>
<div class="form-row">
    <div class="form-group col-12 col-md-12">
      [textarea* textarea-127 class:form-control placeholder "MENSAJE *"]
    </div>
</div>
[submit class:btn_custom "Enviar"]