Getting permission for incoming connection RDS MySQL on VPC

I have created a MySQL db instance on AWS's RDS, with following configuration:

Supported platform : VPC EngineName of the database engine to be used for this instance: MySQL 5.1.73a Instance ClassContains the compute and memory capacity of the DB Instance:

db.t1.micro The instance shows error for "no inbound connection" as i have to create securtiy group using VPC Wizard. I have calculated the CIDR block from an online tool and but i don't know how to get Public Subnet for my IP Address All the help article are useful for EC2 instance but the origin i choosed is supporting VPC only..