How to rollback from 7.3 to 6.2.2

Elastic Stack Elasticsearch
1

After upgrade from 6.2.2 to 7.3 and if we face any issue ,
how to rollback to olderversion of 6.2.2 from 7.3?

2

Welcome.

You can not rollback. You need to reindex everything.
If you have backups, then you can just restore.

3

Thanks