Ec2 instance opened port not connecting from certain regions

Solution for Ec2 instance opened port not connecting from certain regions
is Given Below:

I have installed SQL Server in an AWS instance (Ubuntu) and it is working perfectly but found that it is not able to connect to the database from certain IPs (from that region not working for any ISPs). My port 1433 is open and I am able to access it from my system. Here is my security group configuration: enter image description here
But in my friends system which is in a different network it is not connecting though I can access port 80 from that system. I telnet that port (1433) and it is throwing “could not connect host”. I tried tracetcp and after 9 hops the requests are timed out. I used VPN in that system and it got connected.

Not able to determine what could be the issue. Not a network pro and any help is highly appreciated.