Type search words and press enter
"Use Edit Log for transactions/masters, and digital signature for invoices/reports with Release 2.1. Download NOW!"
https://help.tallysolutions.com/docs/te9rel66/Tax_India/excise-importer/ei-automate-calculation-customs.htm

Automating Calculation of Customs Duty (Excise for Importer)

Y ou can automate the calculation of custom duty, CVD ( Countervailing Duty) or any additional duty on imports and clear the goods under Bill of Entry by defining the rate at the ledger master level for each of the duty type.

Select this ledger master along with the stock item while recording a purchase invoice.

Refer How do I configure a ledger for custom duty? to know how to create a ledger for custom duty.