Can we migrate data from QBO (India) to QB Desktop (India) with attachments having links to the vouchers intact?

Hello there, @DG_99.

The ability to migrate data from QuickBooks Online (QBO) directly to QuickBooks Desktop (QBDT) is unavailable in your region.

Also, QuickBooks products are not available in India. You can read this article for more information: Discontinuation of QuickBooks in India. 

In case you're using other accounting software, simply export your QBO data and import them via a third-party application. 

Please don't hesitate to leave a reply below if you have any other concerns about migrating your QuickBooks data. Have a good one and stay safe. 

@DG_99 

What do you mean with QB Desktop (India)?

Your time is up and your best option now is to use the exporter tool to export CoA , Lists and Transactions to CSV files.

https://get.transactionpro.com/qbo

Then you may consider to purchase a 3rd party service to convert your data to QBO Global version, QB Desktop US version or another cloud based accounting app (e.g Zoho Books).