Are you trying to install this client for a specific server, or Configs-For-NightX-Client/Hydracraft at main - GitHub
This folder must be placed inside your .minecraft/versions directory. Tifality.jar : The actual executable code for the client. Tifality.rar
Optional JavaScript or Lua scripts to add custom modules. Are you trying to install this client for
The configuration file that tells the Minecraft launcher how to run the JAR file. Tifality.rar
Run the client in a virtual machine or use a launcher like Prism Launcher which keeps instances isolated.