i have override  "report_invoice_document" template in report_invoice.rml. I have removed  <t t-call="report.external_layout"> line and </t> . I have added header lines before class="page" div tag.. 

<template id="account.report_invoice_document">
<div class="header">
    <div class="row">
            <div class="col-xs-3">
                <img t-if="o.company_id.logo" t-att-src="'data:image/png;base64,%s' % o.company_id.logo" style="max-height: 150px;"/>
            </div>
        </div>
        <div class="row zero_min_height">
            <div class="col-xs-12">
                <div style="border-bottom: 1px solid black;"/>
            </div>
        </div>

</div>

These lines working fine.........

I have added footer lines after end of the class="page" div tag. But this footer not displaying in the report. Can any one help me please?. I can see this footer when i add these footer in the class="page" div tag. But it's not showing like a footer...

<div class="footer">
        <div class="text-center" style="border-top: 1px solid black;">
            <ul class="list-inline">
                <li t-if="o.company_id.phone">Phone: <span t-field="o.company_id.phone"/></li>

                <li t-if="o.company_id.fax and o.company_id.phone">&amp;bull;</li>
                <li t-if="o.company_id.fax">Fax: <span t-field="o.company_id.fax"/></li>

                <li t-if="o.company_id.email">&amp;bull;</li>
                <li t-if="o.company_id.email">Email: <span t-field="o.company_id.email"/></li>

                <li t-if="o.company_id.website">&amp;bull;</li>
                <li t-if="o.company_id.website">Website: <span t-field="o.company_id.website"/></li>
            </ul>
            <ul class="list-inline">
                <li>Page:</li>
                <li><span class="page"/></li>
                <li>/</li>
                <li><span class="topage"/></li>
            </ul>
        </div>
    </div>