Due to Indonesia requirement to register phone's IMEI code, unregistered phone may/maynot be able to detect a local SIM card.
In such case, you can do one of the following:
1. Rent a mobile WiFi to use the local SIM. This is also a cost-effective way to share data and it's hassle free (no registration needed)
2. Go to telecom store to register your phone's IMEI