To complete GST registration in Tirupur, verify your Ward/Circle/Sector on the GST portal based on your business address. Go to the government portal, navigate to 'Services' > 'Search Taxpayer' > 'Search by location,' and input your business address details. This will help you identify the correct jurisdiction for your GST registration. Ensure that the information you provide aligns with your business location for accurate registration and compliance with the GST guidelines.