How to create custom layout in liferay 6.2

Creating the custom layout through eclipse will not work because eclipse is not upgraded with boothstrp

For this you have to create layout manually not by dragging the colomns in .tpl you have to go to source in .tpl file and write the code manually.

Here is the custom layout for 20-60-20

<div class="Sample" id="main-content" class="container-fluid" role="main">
<div class="portlet-layout row-fluid">
    <div class="portlet-column portlet-column-first span2" id="column-1">
        $processor.processColumn

         ("column-1", "portlet-column-content portlet-column-content-first")
    </div>
    <div class="portlet-column portlet-column-last span8" id="column-2">
        $processor.processColumn

           ("column-2", "portlet-column-content portlet-column-content-last")
    </div>
    <div class="portlet-column portlet-column-last span2" id="column-3">
        $processor.processColumn

         ("column-3", "portlet-column-content portlet-column-content-last")
    </div>
</div>

I hope this will help you