you said you disabled DHCP in
Netgear.. and its not working.. well it wont work because airtel DHCP is off.. and netgear DHCP is off too.. so who will give the ip ??

.. try this.. connect a LAN cable from airtel modem to your pc directly and manually configure the ip address of your machine as 192.168.2.4 .. and gateway as 192.168.2.1 .. and then try .. also in the airtel port forward settings.. change the ip from 192.168.1.20 to 192.168.2.4 ..
you would need to do some experimenting to get this work!!!
no mate its not working

, i tried to disable DHCP and gave the settings manually but it ended in a vain , i even port forwarded to my , when i enter my ip
http://65.45.45.xx , if the port forward is sucessfull , it should have shown my welcome screen , but it tries to login into my
router , so i guess the port is not properly forwarded , do i need to change some other settings
I even tried DHCP enabled , but that too not working!
Between i tried all by connecting the airtel modem directly without netgear!