Which of the following companies are required to appoint Internal Auditor to conduct internal audit of the functions and activities of the company?

Section 138. Internal audit- (1) Such class or classes of companies as may be prescribed shall be required to appoint an internal auditor, who shall either be a chartered accountant or a cost accountant, or such other professional as may be decided by the Board to conduct internal audit of the functions and activities of the company. Companies (Accounts) Rules, 2014- 13. Companies required to appoint internal auditor: (1) The following class of companies shall be required to appoint an internal auditor or a firm of internal auditors which may be either an individual or a partnership firm or a body corporate , namely:- (a) every listed company; (b) every unlisted public company having- (i) paid up share capital of fifty crore rupees or more during the preceding financial year; or (ii) turnover of two hundred crore rupees or more during the preceding financial year; or (iii) outstanding loans or borrowings from banks or public financial institutions exceeding one hundred crore rupees or more at any point of time during the preceding financial year; or (iv) outstanding deposits of twenty five crore rupees or more at any point of time during the preceding financial year; and (c) every private company having- (i) turnover of two hundred crore rupees or more during the preceding financial year; or (ii) outstanding loans or borrowings from banks or public financial institutions exceeding one hundred crore rupees or more at any point of time during the preceding financial year: Provided that an existing company covered under any of the above criteria shall comply with the requirements of section 138 and this rule within six months of commencement of such section.