Hi yogesh,

For the repetition of header you need to call your custom layout(Header/footer) before page.(report_extended/my_mrporder_report.xml)

<?xml version="1.0"?>
<t t-name="report_extended.my_report_mrporder">
    <t t-call="report.html_container">
        <t t-foreach="docs" t-as="o">
            <t t-call="report_extended.my_own_layout"><!-- This will repeat header/footer in each page-->

                <div class="page">
......

 Hope this will help you.

---------------------------edited for extra information

If you need to create your own layout, you can simply create it in your custom module.

Just put you layout code in your report file. like...(report_extended/my_mrporder_report.xml)

<template id="my_own_layout">
    <!-- Multicompany -->
    <t t-if="o and 'company_id' in o">
        <t t-set="company" t-value="o.company_id"></t>
    </t>
    <t t-if="not o or not 'company_id' in o">
        <t t-set="company" t-value="res_company"></t>
    </t>
    <t t-call="report_extended.my_own_layout_header"/>
    <t t-raw="0" />
</template>
<template id="my_own_layout_header">
    <div class="header">
        <div class="row">
           <h1>MY HEADER</h1>
        </div>
    </div>
</template>

Here report_extended is your custom module.

Do not hesitated to ask more...