Some forms aren't available to be E-filed yet. This could be because the IRS and/or State haven't released the form to be electronically filed. Once they do release it, it might take a few days for TurboTax to integrate it into the system.
If the form says it's Unsupported, it means that it is not supported by TurboTax, and you won't be able to file it electronically. Instead, you will have to print and mail either the form itself or the whole return.
Click on the link below and then on the blue "This Tool" link, and locate your state for when a specific return or Form will be available to be e-filed (if the form isn't supported by TurboTax you will need to file by mail):
When will my individual tax forms be available in TurboTax?