You can create a new Batch from:

Stock > Documents > Batch > New

For the Batch item, updating Batch No. in the stock transactions (Purchase Receipt & Delivery Note) is mandatory.

Purchase Receipt 

When generating a Purchase Receipt, you have the option to either create a new batch or select an existing batch master. Each batch can be linked to a single batch item.

Delivery Note 

Specify the batch in the Delivery Note Item table. If a batch item is included in the Product Bundle, you can also update its batch number in the Packing List table.

Batch-wise Stock Balance Report 

To check batch-wise stock balance report, go to:

Stock > Standard Reports > Batch-wise Balance History