First For clarity on 140 (4)
 
140(1)
— > if removal is before AGM that means his report (if any) wont be used at AGM– opportunity of being heard + BOD Resolution + CG Approval + Special Resolution
140(4) 
—- > if removal is at AGM (resolution is proposed no to appoint retiring auditor or to appoint new auditor ) 2 / 3 / 4 / 5 / 6 (Not Reappointed) — Special Notice +  Auditor Intimation + Representation Letter + Circulation + Ordinary Resolution 
 
139(1) & CAAR Rules
—> if at AGM , resolution was to ratify old auditor but resolution failed to pass at AGM then it is no ratification and board will appoint
 
Second for 139 (9) & (10)
139(10) :- It talks about automatic reappointment if no appointment in last AGM of retirement 
139(9) :- It is made so that wrong appointment should not take place through 139 (10), hence it says no to eligibility to re-appoint in 3 cases
— person disqualified
— unwillingness given in writing
— special resolution already passed by company to appoint someone else 
 
above are made to avoid wrong appointment in automatic appointments