1.Airtel Working Trick for blocked sim 100% working
Use below settings in default browser,
Proxy- proxybrowse.net
Port- 80
Homepage– ic.bsbportal.com
Apn- airtelgprs.com

2.Airtel Trick for blocked and unblocked sim
Setting on Phone:
Proxy : server4.operamini.com
Port : 80
APN : Airtelgprs.com
On OPERAMINI handler,
Proxy type : HTTP
Proxy Server : ic.bsbportal.com
Tested by me working in West Bengal , JK and many more states