Hello satya as per literal interpretation of companies act only officers and employees of that company cannot do audit of the company other can do it. That means as per companies act directors of holding can do audit of subsidiary company.
but as per CA Act CA cannot accept directorship of holding company if his partner is auditor of subsidiary. so if he himself is auditor of subsidiary he should not accept directorship of holding.
 
final conclusion company act is not having direct restriction on CA being holding company director and subsidiary company auditor but CA Act restricts such thing. so it is not possible.