AWS Schema Conversion Tool (SCT) is one of the must tool for a successful migration of databases to AWS RDS.
If you are trying to connect to MySQL hosted on EC2 instance or RDS and unable to make the connection despite of setting the security groups correctly and making sure that port, hostname, username and password are right, then first check the log of SCT.
If you are trying to connect to MySQL hosted on EC2 instance or RDS and unable to make the connection despite of setting the security groups correctly and making sure that port, hostname, username and password are right, then first check the log of SCT.