Can family members follow into US at a later date OR do we need to enter together?

[MikeMM]

After successful CP interview, can family members follow into US at a later date Or do they all have to enter into the US together with me, the main applicant?
If they can enter later within the 6 months, what docs do they require to show at POE? Passport with the Immigrant Visa + their Yellow Envelope?
Do they have to show any documents of myself?
Thanks

 

[LucyMO]

the winner must enter either first, or at the same time with the rest of the family.