Tax audit for cng pump dealer

Dear All,

We are CNG Pump Dealers of Mahanagar Gas Limited (MGL). MGL deducts TDS on our fees U/s 194C @ 2%.  Our turnover per year is approx 90 lacs. So, we wish to know whether we will be liable for Tax Audit or not? Will be be classified as Profession or Business? Request you'll to explain in details. We mention in the invoice as 'Service Charge for Dispensing the  CNG'

Thanks