You cannot aggregate batches with different statuses i.e few batches in Draft and few batches in Deferred statuses.
When you aggregate the batches, certificates from all the selected batches are moved under the new batch. And the selected batches go into Cancelled status. You can then use the new batch to proceed with your payments.
1. Select the batches you want to aggregate from the batch listing page - You will see a check box against the batches which are either in Draft OR Deferred status.
2. Click on the button. Note that the will get enabled ONLY if you select 2 OR more batches to aggregate.
3. Confirm your action by clicking on OK.
4. You will get a success message(as shown in image below) and click on the to get the batch details for the new aggregated batch
5. You will see the batch details page, all the certificates of the batch and an option to proceed with the payment. The rest of the process remains the same.