When I open onion relay on Tails , and then open Electrum Wallet on LiveCD Tails Does that Electrum connected with Tor proxy/network?
Hope some users would help me to explain this things
Tails by design forces every connection to pass through the Tor network, the Tor service starts automatically as so this does not need user interaction. If you're connected to the Tor network you should see the usual green onion, otherwise this is the right place to ask (but in another question).
Please note that if tails cannot connect the Tor network, also Electrum Wallet will not be able to connect to its network.