A 2012 tax data file, with a file extension of .tax2012, can only be opened by the TurboTax software for tax year 2012.
TurboTax does not support tax year 2012.
There is a service which can convert the tax data file from 2012 to a PDF for a fee. This service is not associated with Intuit/TurboTax so use at your own risk. Go to this website - https://www.taxprinter.com/