Identity and Access Management (IAM) provides the way to grant privileges on different AWS resources to IAM Users and, certainly, you can control access to the RDS using IAM. You can provide access to the RDS to only those users who need it. But be aware of the fact that you cannot control the database's internal access using IAM; you still need to use the database engine specific grants to control access to the database and schemas. IAM controls who can access the RDS service, create databases, modify database configuration, and drop those databases; but individual database user creations grant to those users, and applications, specific user access, and restrictions will be controlled at the individual database level.
