I have used pyinstaller to make my script executable and now I want it to run on every login/startup. The gnome tweak tool is not listing my executable. How can I achieve this?
You are asking 3 questions here. Startup and login are not the same.
1) To have a script run on login you might add it to .bash_profile (hidden file in your user's home directory): https://ask.fedoraproject.org/en/question/35263/execute-shell-script-at-login/
2) To have the script run on startup (boot) you may choose to create an /etc/rc.local file (https://ask.fedoraproject.org/en/question/26898/what-is-the-auto-start-file-like-rclocal/)
make sure it is executable:
chmod +x /etc/rc.local
enable the service:
systemctl enable rc-local.service
3) Run 'gnome-session-properties' and add your script there.