When will you come back?

[Polyester]

In the condition sentence, for example,
1. When will you back home?

2. When you back home?

P.S I'm waiting my family back home, which one is suitable for these situation?

 

[emsr2d2]

Neither sentence is correct.

1. When will you be/get back home?
2. When are you due back home?

The first is the more natural of the two.

I assume you mean "conditional", not "condition" but neither of those questions are in the conditional.

 

[GoesStation]

I'm waiting my family back home.

You have to write either awaiting or waiting for my family. "Awaiting" is rather formal and old-fashioned, at least in AmE.