When picking up a phone call...

[salt&pepper]

When picking up a phone call for my colleague...
Do I use:
1) He is engaged on the line.
2) His line is engaged right now.
3) Any suggestion?

[emsr2d2]

When picking up a phone call for my colleague...
Do I use:
1) He is engaged on the line.
2) His line is engaged right now.
3) Any suggestion?

If he is actually speaking on the other line, then choice 2 is best. I would say that "right now" might still be considered AmE, so in BrE we would say "His line is engaged at the moment."

Number 1 doesn't work. We don't use "He is engaged" in this way in this scenario. It's the phone line that's engaged.

I would follow "His line is engaged at the moment" with either "Would you like to hold?", "Would you like to call back later?" and/or "Can I get him to call you back?"

[billmcd]

When picking up a phone call for my colleague...
Do I use:
1) He is engaged on the line.
2) His line is engaged right now.
3) Any suggestion?

In AmE you would seldom/never use/hear the term "engaged" as used in your example. Rather, you would most often hear "He's on the phone right now" or "He's on the other line right now".