tally facilitates multi currency entry in tally. it help users to enter import and exports in other currency then the base currency. each transaction will automatically determine the profit/loss on each forex Explore Tally.erp 9 
If you are engaged in import-exports of goods/services, then you should set your local currency as base currency for all your foreign suppliers/customers otherwise you will not be able to get bill wise details.Read how to get bill wise details in tally.erp 9for imports and export transaction Explore Tally.erp 9 a detailed article helping to learn how to enter multi currency in tally.erp 9 to record forex transactions resulting out of import and export. Forex transactions generally being done in an international currency like USD $ Explore Tally.erp 9