How to appoint auditor in company

Auditor
Definatin :
"An auditors is a person appointed examine the books of accounts of a registered company and to report upon them to company members"
Appointment criteria of auditor :
    The appointment of auditor of a company is made according to the provision of the section 252 who explained below 
Statutory Auditor

 First auditors
subsequent auditors
casual vacancy

First auditors
"Auditor,who is appointed at the time of  incorporation of the company, hold office until conclusion of the first annual general meeting  known as first auditor"

 By B.O.D section 252 (3)
By Share holder 252 (3b)
By SECP 252(6)(7)
By B.O.D section 252 (3)
      For a newly incorporation co. the first auditors is appointed by the directors within 60 days of incorporatuion and auditor shall hold the office untel the conclusion of first annual general meeting 
By Share holder 252 (3b)
   if the directors fail to appoint the auditor within 60 days at the time of incorporation
, shareholders are eligible to appoint the auditor with in next 60 days .
Subsequent
First auditor satnds retired on the conclusion of the first annual general meeting,thereafter is appointed by members in annual general meeting known as subsequent
by shareholder 252 (1)
by secap 252(6,7)

casual vacancy
where the auditor of the company dies or a form of auditor is dissolved or the auditoris unable to work as an auditor is unable to work as an auditor, there arises a casual vacancy in the office of auditor