Can't Connect to Amazon RDS MySQL Instance from anywhere Except Home

I am working on a school project in which we need to perform Statistical Analysis in R. For the sake of the project, I have created an Amazon Web Services RDS MySQL instance, that I would like to share with my colleagues.

I have already uploaded the data that we need for our project in the database and can connect to the instance via both the MySQL Client and R from home. However, I cannot connect from either School or any Local Café via either the MySQL Client or any Local Café.

I have configured the Security Group so that anyone can access the database (both Inbound & Outbound). The Port that I use is 1433.

Anybody has an idea how I can resolve the problem?