tax audit requirement

First of
Is Your business is eligible u/s 44ad...?

a. If you continue to follow 44AD for FY 18-19, audit is compulsory.

If you discontinue 44AD then No Audit but 44AD won't be allowed for next 5 years

b. Without 44AD that is under regular business income - there will not be Audit as well as no restrictions on profit %age. Books of account compulsory and ITR3 .