Hai to all,
I will create a group 'Commission' through xml. then there is any way to add users to this group through the cod(python code) or csv file. this is xml file for creating group
<record model="ir.module.category" id="module_category_commission">
<field name="name">Commission</field>
<field name="description">Salesmen Commission Table</field>
<field name="sequence">20</field>
</record>
<record id="salesmen_commission_group" model="res.groups">
<field name="name">Commission</field>
<field name="comment">Salesmen Commission Permission Group.</field>
<field name="category_id" ref="module_category_commission"/>
</record>