Take both connections vi.. It will mostly work without recharge also... They credit 1gb/day for 7 days per. Month.... And 90% of time incoming is active.....
In airtel incoming wil stop the day the recharge ends... No workaround... And in Mumbai circle 2g is good for vi
Airtel and Vi don't seem to deactivate the connection even after no recharge for over a year or more. G-Gowda reported his Airtel no.(s) being alive despite 4+ years of no recharge. Vi does send messages regarding deactivation due to non-usage occasionally but also mentions Rs 20 deduction to keep the no. alive. Anyway since Vi keeps on crediting free OG for 3/7 days almost every month it's easy to keep the no. active by just making 1-2 OG calls in a month. IC SMS doesn't stop excluding some circles but it doesn't count anyway. Maintaining balance above Rs 20 is a good move. In my case IC calls stop immediately after IC expiry whether after a recharge or after the freebie expires.
Jio is much more unpredictable but recharging with Rs 119 once every 90 days should be enough. Both IC calls and SMS could continue to work after service expiry. Reportedly as long as the SIM is inserted in a device and hence continuing to access the network Jio is more lenient.
If you have any spare jiophone (or can source one), port to jio, put SIM and recharge 26 (2GB data only for 28 days) , then after expiry, recharge on 80th day to be safe (they purge after 84 days if rules are followed strictly). Can be used on other 4G phones for receiving calls+sms, only recharging needs jiophone.