Gst audit for tax free goods businesse.

i am involved in tax free goods (garlic n onion) business tax free goods turn over is around 10 crore .i have purchase also packing material as bardan around 20 lack in last financial year for packing garlic no other taxable goods sales . packing material is consumed in garlic Gst audit is compulsory for my business. what i am liable for Gst audit.