GST AUDIT ?

I think yes. we have to do AUDIT

Yes because exempt supplies includes non taxable supplies

If you are registered & your aggregate turnover (Exempted or Taxable or both) exceeds 2crore is required GST audit (As per Section 35 CGST Act & read with Defination of Aggregate turnover in Section 2(6) of CGST act )

Agree with Pankaj Sir...

Aggregate Turnover as defined u/s 2(6) of the CGST Act 2017, includes EXEMPT SUPPLY.

Therefore, if your Aggregate Turnover exceeds Rs. 2 crore, you have to file FORM GSTR-9C ( Reconciliation Statement and Audit Report ) as per the Provision of Section 44(2) of the CGST Act 2017 read with Rule 80(3) of the CGST Rules 2017 and get it certified by a Chartered Accountant or a Cost and Management Accountant by virtue of Provision of Section 35(5) of the CGST Act 2017.

NOTE : If you are dealing in "EXCLUSIVE SUPPLY OF EXEMPTED GOODS" , then your are not required to take GST REGISTRATION as per Section 23 of the CGST Act 2017.