SCN of new gst registration

Dear experts,

I am providing caren designing services also engendering services for process equipment's.

Now my threshold limit is blow 20 lakh but one client give me order for manufacturing of caren and client wants gst bill.

SCN issued regarding place of business. Currently I am providing design service in my home also we will give outside person for manufacturing of caren and provide to my client.

The officer issued SCN due to my address of principal place of business is my home address.

Please tell how I can give replay to scn.

Thanks & Regards.