Answers for "how can i center column in row in bootstrap"

align eliment in center of row bootstrap

<div class="row justify-content-center">
  ...inner divs and content...
</div>

Center a Column in Bootstrap

How to Center a Column in Bootstrap

Use the mx-auto Class

Example
<div class="container">
    <div class="row">
        <div class="col-sm-6 mx-auto">
            <!-- Column content -->
        </div>
    </div>
</div>