In Tally.ERP 9 you can import data from earlier versions of Tally, Tally.ERP 9 and any third party application using the predefined format of XML.
Go to Gateway of Tally > Import of Data
The Import of Data menu is displayed as shown.
To read more on the step by step procedure for importing masters, vouchers and synchronization click one of the corresponding links:
Masters
Vouchers
Synchronization