Hello,
If it is possible to directly import data from Tally ERP database, you can even connect with SSIS or http://www.kodyaz.com/articles/sql-server-script-data-with-generate-script-wizard.aspx.
But I did a similar data transfer in SAP system recently, I had to use a ABAP program and a Function Module for this transfer.
And I think this seems to be a correct way if the business logic running is complex on top of the ERP database.