If you need to restore the Tally 7.2 data from the backup, you can do so by using the Tally.ERP 9 Data Migration Tool. You can then migrate the restored data to Tally.ERP 9.
To restore the backup of data created in Tally 7.2
Select Restore 7.2 Backup.
In the Restore Companies on Disk screen, enter the path for:
Destination: The folder where the data backup has to be restored.
Source: The folder which contains the backed up data.
Select the company which has to restored from the List of Companies.
Select Yes to Accept restoring the data backup.
The restored data of Tally 7.2 is available in the destination folder.
Proceed with Migrating Data to Tally.ERP 9.