yeah. bridge model lets you connect your own router to that device and configure the connection on that router instead of airtel's own device. airtel does allow that. contact customer support. tell them to enable bridge mode on your connection and send a technician to your place to configure your router.
third party onu might not work as airtel might be restricting it to their own devices. some isps do let them work by copying the serial number from the device provided by them to your own device. easier would be get airtel to enable bridge mode and use their own device as onu and setup the connection on your own router. with bridge mode, airtel's router would essentially work as a dumb onu.
they didn't turned the bridge mode on and there technician also know how to do it then one sir gave contact of pune's airtel technician talked to him he guided me and i saw the option of bridge mode in WAN2 in wan connections but when i enabled it and deactivated the WAN0 (PPPoE) and entered the ID and Password same as i seen in WAN0 and dynamic ip was on but still the internet is not workin' can anyone explain in step by step method i'd be grateful thank you for reading.
edit : lan cable that i got in Netgearrouter when i purchased it i used that for connecting two router ( netgear = wan port | airtel router = lan1,2,3,4 ) tried every port didn't work.