hi vadivel,

class sale_order(osv.osv):
    _inherit = 'sale.order'
    
    _columns={
                'state': fields.selection([

            ('quot_confirm', 'Confirm'),
            ('draft', 'Draft Quotation'),
            ('sent', 'Quotation Sent'),
            ('cancel', 'Cancelled'),
            ('waiting_date', 'Waiting Schedule'),
            ('progress', 'Sales Order'),
            ('manual', 'Sale to Invoice'),
            ('invoice_except', 'Invoice Exception'),
            ('done', 'Done'),
            ], 'Status', readonly=True, track_visibility='onchange',
            help="Gives the status of the quotation or sales order. \nThe exception status is automatically set when a cancel operation occurs in the processing of a document linked to the sales order. \nThe 'Waiting Schedule' status is set when the invoice is confirmed but waiting for the scheduler to run on the order date.", select=True),
                              
                }
    
sale_order()