We have around 7000 pages in wagtail. We are using version 2.10.X. How can I bulk localise and translate these pages in wagtail. We tried using direct SQL queries but its difficult to handle for different types of pages table and relations between them and auto generated columns.
I suspect you will need to build custom export/import scripts for this. What format would be the most convenient for whatever you are using for the translations? If it is something that can use JSON, then exporting the data using the Wagtail API v2 might help with the first part. However, the built-in API is read-only so you will need to build your own import portion - perhaps using Django Rest Framework.
If it is at all feasible, I would upgrade your Wagtail install BEFORE doing the translation work. Wagtail 2 is no longer supported and having more content in place before doing the upgrades will just make them more difficult.