Can two networks with same IP address be connected?

Yes if you use a switch and connect it to your modem, then add two routers to it, you can have more than one networks using the same iP address but putting more stress on your modem. But two computers on the same network cannot have the same local IP or every packet that gets transmitted will be corrupted by sending half and half to both machines on the network making internet access glitchy or unusable.