RDS Custom for SQL Server lets you Bring Your Own Media

Amazon Relational Database Service (Amazon RDS) Custom for SQL Server now allows customers to use their own SQL Server installation media when creating an instance. By using Bring Your Own Media (BYOM), customers may leverage their existing SQL Server licenses with Amazon RDS Custom for SQL Server. Amazon RDS Custom is a managed database service that allows customization of the underlying operating system and database environment. Managed features of RDS Custom for SQL Server include Multi-AZ deployment, point-in-time recovery and more.

Source:: Amazon AWS