Themes not visible in Unity Tweak Tool

After extracting the archive, you'll find Aurora and Dark Aurora folders there. You have to put them in either ~/.local/share/themes or /usr/share/themes directory.

However, I saw that they don't appear in Unity Tweak Tool. The solution is using Gnome Tweak Tool to set the theme.

To install it -

sudo apt install gnome-tweak-tool

Open and set the theme from Appearance Section.

Update after further information It appeared OP's .local folder was owned by root. To get the ownership use sudo chown -r your-user-name ~/.local before copying the theme folder. Then use cp without using sudo.