Check out example codes for ".col-6 bootstrap". It will help you in understanding the concepts better.

Code Example 1

.col-6{
	flex: 0 0 50%;
	max-width: 50%;
}

Code Example 2

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


<div class="row">
    <div class="col-md-4">
        <div class="well">1
            <br/>
            <br/>
            <br/>
            <br/>
            <br/>
        </div>
    </div>
    <div class="col-md-8">
        <div class="row">
            <div class="col-md-6">
                <div class="well">2</div>
            </div>
            <div class="col-md-6">
                <div class="well">3</div>
            </div>
        </div>
        <div class="row">
            <div class="col-md-6">
                <div class="well">4</div>
            </div>
            <div class="col-md-6">
                <div class="well">5</div>
            </div>
        </div>
    </div>
</div>
<div class="row">
    <div class="col-md-4">
        <div class="well">6</div>
    </div>
    <div class="col-md-4">
        <div class="well">7</div>
    </div>
    <div class="col-md-4">
        <div class="well">8</div>
    </div>
</div>

Code Example 3

<div class="col-lg-3 mb-4">

Learn ReactJs, React Native from akashmittal.com