Let's say I'm using both tbb and torify at the same time. For e.g. I'm using tor to browser/look at tor.stackexchange.com. At the same time I am running torify on a different url say https://aaa.bbb.ccc (just a hypothetical url at moment, although it probably might be registered by a domain hoarder but that's a different topic) . Now in such a scenario would both be using the same cricuit, nodes, path etc. or would both use different circuits '
No, Tor Browser isolates it's circuits by the first party domain.
e.g. foo.com, bar.foo.com and qux.bar.foo.com will all be isolated on their own circuit for foo.com. While example.com, bar.example.com and qux.bar.example.com will all use their own isolated circuit for example.com.
torify won't use the same SOCKS5 credentials and so won't use the same circuit. However, multiple applications under
torify will share the same circuit since it doesn't perform any kind of isolation by default. Advanced configuration of
torsocks) will allow for isolation, if required.