If you want to know that your phone supports 3G or not. You can go into the settings of your phone and look for network settings, see if it has any of the options available. 3Gs, UMTS, WCDMA, HSPA, HSPA+. If it has, then your phone is 3G enable. Don’t worry if it has not, you can look into the phones listed below.
The second way is that you can look into the below list to see if your phone is 3G enabled.
How to enable 3G on my phone?
There’s certainly a way if you think that 3G is not enabled in your mobile phone.
Samsung Android Phones
Go into settings, connection, more network, mobile networks, network mode, WCDMA/GSM
Other Android Phones
Go into settings, more, mobile network, preferred network type, WCDMA/GSM
Windows Phones (Nokia Lumia, HTC etc)
Settings, Phone, Network Mode, Select 3G
iOS6, iOS7: Settings, General, Mobile Data, 3G/4G
iOS5: Settings, General, Netwok, Cellular Data
Settings, Connections, More Network, Mobile Networks, Network Mode, WCDMA/GSM