can I call on a phone, using hangouts, which is not connected to data?

[AC Question]

Hello,

I have an android phone (MotoG2), primarily used by my kids for gaming.

It does not have a SIM card in it and is connected at home, using WiFi.
Outside (home), I enable my phone (Xiaomi Redmi Note 3) as a hotspot and then my kid's phone connects through it.

The MotoG2 has my daughter's gmail account configured in it.

I am unable to find the MotoG2, since morning.

I am trying to call my daughter on hangouts (on MotoG2), using my Redmi phone and I hear the call trying to connect!

I want to know, will the phone (hangouts) ring, if it is not connected to network?
I am asking this, because,
1) I am assuming, that I have lost the phone
2) It would be traceable, only if it connected to the WiFi at home or to the hotspot of my Redmi phone.
3) I checked with the Android Device Manager, it is unable to locate it today.
4) I tried calling on hangouts (my daughter's gmail account), and it could hear the call progressing.

So, my question is, if it does not have a SIM card (no data), is not connected to WiFi and is also not connected to a hotspot, then is the call going on hangouts reliable, to understand that the phone (google account), is actually receiving a call?

Please help.

Thanks and Regards,
Suparna