https://help.tallysolutions.com/docs/te9rel64/Voucher_Entry/Order_Processing/Enabling_Order_Processing.htm

Enabling Order Processing

To enable purchase order, sales order, and job order processing in Tally.ERP 9, you have to activate the required features in F11: Features ( F2: Inventory Features ).

Enable the following features in the Order Processing section:

Enable purchase order processing

Allow Sales Order Processing

Enable job order processing

Note: When Enable job order processing is set to Yes , the options Maintain multiple Godowns and Use material in and out vouchers get enabled automatically.