JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>

<div class="container">
    <div class="row row-center">
      <div class="col-xs-2 col-center">b</div>
      <div class="col-xs-2 col-center">d</div>
      <div class="col-xs-2 col-center">b</div>
      <div class="col-xs-2 col-center">d</div>
      <div class="col-xs-2 col-center">d</div>
      <div class="col-xs-2 col-center">d</div>
    </div>
  </div>

CSS

.row-center {
  text-align: center;
}

.col-center {
  display: inline-block;
  border: 1px solid blue;
  text-align: left;
}

.container {
    display: flex;
    align-content: center;
    justify-content: center;
}