Duplicate page in erpnext

is it possible to create a duplicate page for the existing http://localhost:8000/desk#query-report/Balance Sheet? .How is it possible?Please help me

Yes, you can do it inside your custom apps.

For reference you can check https://github.com/frappe-apps/rigpl-erpnext/tree/master/rigpl_erpnext/rigpl_erpnext/report

It is a custom app made by Rohit Industries.