AWS RDS: How to access/connect to RDS MySql DB From localhost

I am very new to Amazon Web Services, I have created Mysql DB on RDS and stored some data. Now i want to connect to RDS db from localhost(which is in running on my desktop) ,Tried as fallow in my PHP connection. $con = mysql_connect("XXXX.XXXXX.XX-XX-X.rds.amazonaws.com:3306", "XXX", "XXX");

But getting error as fallows Could not connect: Can't connect to MySQL server on 'awsniti.XXXX.rds.amazonaws.com'

Also tried giving my local IP address to Inbounds of Security Group. But couldn't connect.

googled a lot, but not able to find right answer.

Please help me with this issue.

regards, Kiran