As per section 144 of companies act 2013, auditors are not allowed to render certain services like
(a) Accounting and book keeping services
(b) internal audit
(c) design and implementation of any financial service etc
further As per section 147(1) of companies act 2013, if any of the provision is contravented (it includes section 144) the company shall be punishable with fine which shall not be less than twenty-five thousand rupees but which may extend to five lakh rupees and every officer of the company who is in default shall be punishable with imprisonment for a term which may extend to one year or with fine which shall not be less than ten thousand rupees but which may extend to one lakh rupees, or with both.
Further more as per section 147 (2), if auditor contravenes ( Includes above mention section 144) then he shall be liable with a fine of not less than 25 thousands but which may extend to 5 lakhs rupees.
Provided that if an auditor has contravened such provisions knowingly or wilfully with the intention to deceive the company or its shareholders or creditors or tax authorities, he shall be punishable with imprisonment for a term which may extend to one year and with fine which shall not be less than one lakh rupees but which may extend to twenty-five lakh rupees.
I have heard a guidelines by Institute for its member regarding the services to be provided. But due to unsurity I am not able to mention those things.
Hope the above reference will be helpful to you.
Regards
Dipendra Prasad Poudel