Can I buy a Iphone 4 & put it on a family mobile plan?

Can I buy a Iphone 4 & put it on a family mobile plan?

If it is an unlocked iPhone 4, absolutely! Make sure you get an officially unlocked iPhone though!

If you have network free iphone 4 means, you will be able to out your family plan.
Locked by specific network means, you will need to unlock your phone. For unlocking visit http://www.mobile-unlocker.com/apple-iphone-4/rs5wp9/ I hope it will be very useful to you.