You need the 2015 version of TurboTax to read a .tax2015 file, but you will not be able to use an online version.
You can find a desktop version at Amazon, for example, but you might not be able to update the program.
https://www.amazon.com/TurboTax-Deluxe-Federal-Buyers-Choice/dp/B01N4PKS8Z/ref=sr_1_2?crid=2H5FVC2FY...
