You should take registration your business is a service ie.taking xerox so you should collect tax @ 18%, on which you can credit your input tax credit ie. yax paid on paper, consumables and capital goods such as printer, plotter, copying machine etc
If more than 20 lakhs... u need to be compulsorily register yourself... u can claim credit on input tax paid on your paper stationery items other consumables stuffs and capital goods like printer
Your business is providing Xerox service, so no composite scheme for you You should take registration at 19 lac and start collecting tax at 20 lacs You can claim input tax on all your paper purchases and stationary expenses