Hi @Dillu06, sorry to hear that. 
Is it the mobile network that you don't have a connection to, or is it a Wi-Fi connection that isn't working?
If it is the mobile network connection, does the device recognize your SIM card? You can also try and search for available networks and register yourself manually on your operators network if you go to Settings > More > Mobile networks > Network operators or Service providers (depending on Android version) > Select a network in the list that appears.
Let me know if that helps! 
