Invoice by contractor

Is Contractor registered under GST ?.

Yes it is registered as regular tax payer under gst

If  contractor  registered  under  GST  then ,  he has to issue  Tax Invoice as per the rule 46 of the CGST 2017 , so all  details are in rule 46 please refer . 

Under the GST Law, there is no specific format of issuing Invoice. So you can make your own format of Invoice but you are required to follow and mention the details in the Invoice as provided under Rule 46 of the CGST Rules 2017. Also refer the Provision of Section 31 of the CGST Act 2017 relating to TAX INVOICE.