Dns server not accessible from another machine

[nitinet]

My issue is when i run the dig command, i am able to get the response when i am running it on the machine. But if i run dig command from other machine, the dns server gets the request and generates the response but i still cant get the response on my terminal.

I ran the following command:
dig @localhost tester.inheap.com A

I have checked the logs and the server is able to process the request.
Also the server is allowed to process the remote request. Nginx serves as the proxy server to the dns server running on port 2000. Please find below the netstat output.

tcp 0 0 0.0.0.0:53 0.0.0.0:* LISTEN 10172/nginx
udp 0 0 0.0.0.0:53 0.0.0.0:* 10172/nginx
tcp6 0 0 :::2000 :::* LISTEN 17415/iotdns
udp 0 0 0.0.0.0:2000 0.0.0.0:* 17415/iotdns

Please help me if there is an issue with any config.