gst return

dear sir,

one of the my client taken GST registration on August 2017, but still now he is not filled any returns he purchase with out gst number and sell to with out gst number total turnover monthly 100000 laks only.

now asking for cancellation I don't need gst registration , bez my turnover below 12 laks,

if file all returns in nil we have to pay the late fees r better to cancel

pl suggest
reg