The suggested solution for FREQUENT DISCONNECTION works on Android Phone where Jio 4G LTE is in Primary SIM Slot on a Dual SIM Handset.
Open Dialer on your Android phone.
Dial *#*#4636#*#*
Click on Phone Info 1
Scroll down and under Set Preferred Network Type as LTE/GSM auto (PRL)
Now Turn OFF Radio & then Turn ON.
Reboot the phone.