For those who have considered the above precautions and still wish to proceed with the download, here's a general guide:
After multiple delays pushed the release date from April 2015 to late summer, and finally to the end of the year, the project was scrapped. The official statement from Warner Bros. confirmed that they could not bring the last-gen versions to the quality standards expected of a Mortal Kombat game. Why There Is No PKG or ISO Download Mortal Kombat X Ps3 Pkg Download
Since an official PKG file does not exist, any website claiming to offer a "Mortal Kombat X PS3 PKG" is likely providing: For those who have considered the above precautions