Since Tlauncher is a third-party software not supported by Mojang, it is very well not within the legal boundaries of the game. so if you download this exe you are committing the act of DIGITAL PIRACY and you may not know, that is fine
DIGITAL PIRACY is the act of downloading and or distributing copyrighted material and intellectual property without paying for it. And it is most certainly an illegal act. Digital piracy is a violation of federal copyright laws. It can result in steep fines and imprisonment. so it Is Vary illegal DO NOT DOWNLOAD RISK OF INPRISONMENT
THIS IS ILLIGAL
it can be legal only if you bought the game on the same pc you are downloading Tlauncher on