Need clarification on which tool to use for migration

Hello.

AWS DMS can be used if you just want to migrate database data in Ubuntu to RDS.
https://docs.aws.amazon.com/dms/latest/userguide/Welcome.html

If you want to migrate applications, OS, etc. to EC2, I think AWS Application Migration Service can be used.
https://docs.aws.amazon.com/mgn/latest/ug/what-is-application-migration-service.html

Thankyou for your response. Is this possible to deploy database in aws cloud directly without using migration tools?

Yes. It is possible.
For example, it is possible to dump database data and import it into RDS.
However, I think that no matter what migration method you use, a large amount of time will be required to verify the operation.