Hi Nadeem-Rajesh,
You can connect outboard gear in a couple of ways on SQ.
1. Using an Insert
Select a channel, go to Processing > Insert and assign the send and return to an output and input socket respectively.
This option is great for dynamics or effects relating to a specific channel (Chorus for example)
2. Using a Mix bus and input channel
Assign Mix Bus 1 to an output socket (or two for stereo mix buses) and an input channel to an input socket. You can now send any channel to the mix bus to route to a reverb (for example), and control the level of the returned ‘effected’ signal using the input channel.
I hope this helps!
Alex