Jio SIM not working in your phone? Some tips to fix it

The SIM is not recognised

-- If this is the problem you face, ensure that you are putting the SIM in a 4G compatible slot. In many dual-SIM phones, only the primary slot -- the number 1 slot is the full-speed, fully supported SIM slow. So, put the Jio SIM in that.
-- Restart your phone.

SIM recognised but no signal

-- Ensure the SIM is in the primary SIM slot (slot 1) if your phone has dual-SIM functionality.
-- Ensure that data is turned on for the SIM. On an Android phone, this can be accessed by tapping on the network sign in the notification shade. on the Mobile Data screen, ensure the data is turned on.
-- Ensure that in the network settings are all good and that you have opted the SIM 1 as your primary SIM for data.
-- Ensure that the phone is set to work with LTE Network. You can do so by going to Settings > Mobile Networks > Preferred network type.

APN setting for jio sim

-- If required, set the APN to Loop Internet. This is accessible only if Jio SIM is getting recognised in your phone. To check this go to Settings > Mobile Networks > Access Point Names.
ADD NEW> APN NAME- JIO> ACCESS POINT NAME-JIONET> 

SIM working but no calls

- Install the Jio Join app from Google Play Store. This will most likely fix the issue. Although, the app currently doesn't seem to work on Android Nougat, in case you have that software on your phone.
Options in case Jio SIM doesn't work in your phone: What are your options in case the Jio SIM doesn't work in your phone and you want to use the Jio network. Two options: get a new phone or get the JioFi, which is a kind of Wi-Fi hostspot router. The JioFi is the cheapest option, although if your phone is too old, something like 3 to 4 years and if you are thinking of replacing it, maybe you can go with a phone that supports 4G  and will work with the Jio SIM.