May I know where can I get the IC 4017 Decade Counter in Multisim Live ?
I need it for making a Traffic Light System .
It seems like you cannot (yet) get the 4017 or any other decade counter from Multisim Live.
Free Subscription users don't have access to counters and even sequential circuit primitives such as latches and flip-flops.
If you have a Premium account, the only counters available as of this time are binary counters, 74LS93N and 74LS193N. You can verify this in Help, Components, Binary Counters.
If you need the 4017 or other decade counter to complete your Traffic Light System, you might find these devices in Multisim (desktop) application.