Hi, @Thyagarajulu B M Welcome to the Microsoft Q&A forum and thanks for reaching out here.
As I understand correctly you are asking if there is a migration tool to migrate databases from Azure SQL Managed Instance to On-premises SQL Server and if it is possible to reverse sync data between Azure SQL MI and On-premises SQL Server.
You can follow this document Here which explains how to restore a database from Azure SQL Managed Instance to SQL Server using the Azure Portal.
Let me know if this document helps or if you need any additional information.
Regards
Geetha