JSFiddle - React, Tailwind, and code Playground

HTML

<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>
<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>

<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>
<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>
    
<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>
<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>
    
<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>
<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>
    
<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>
<input type="checkbox" name="UPDATE_METHOD[]" value="SMS"><div class="name"></div>

JavaScript

var j = 0;

$('[name="UPDATE_METHOD[]"]').prop('name', function(i, name) {
    if (i%2==0) j++;
    return name.split('[').shift() + '['+j+'][]';
});

// show the name for confirmation
$('input').each(function() {
    $(this).next().html(this.name)
});