As aircel sim is now closed or in roaming condition in various region you will still receive calls with these trick
First step
Check there is network showing or not. If not then go to network setting and select manually to airtel ind network.
Second step
When there is roaming on your phone sadly you still can't make call or recive . For receiving call you have to forword all call to your alternative number.
For call forwording
For call forward go to call setting from setting menu and select forward all call and give your alternative number
Final step
Just check its working or not .
If you any problem during this entire process you can comment to The comment section
Get UPC code from below link
ekyc.aircel.com:444/ekyc/genUPC.html
