See this TurboTax support FAQ if you started a prior year tax return with the online editions and need to complete the tax return - https://ttlc.intuit.com/questions/2559403-how-do-i-finish-a-prior-year-return-that-i-started-in-turb...
If you never started a 2016 tax return and want to use TurboTax to complete a 2016 tax return then you will need to purchase and download one of the 2016 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2016 tax return can only be printed and mailed, it cannot be e-filed.
