There is no way anyone here can answer that question.
There is a huge difference between a bare minimal like Arch Linux install ISO (~1G) and the installation ISO’s provided by Ubuntu, Manjaro and others.
Manjaro only provides desktop ISOs.
The ISOs is usually provided in a minimal and full ISO - where the difference is the amount of applications included with the ISO.
To download and verify a Manjaro ISO you can use the python script located at Applications / Manjaro Get Iso · GitLab.
If you want a barebone install ISO there is a community maintained installer-only ISO (~1G) at Releases · manjaro-architect/download · GitHub
dd is the tool to do so (use sudo if not root) - part of coreutils
pacman -Qo dd
dd if=image.iso of=/dev/sdx status=progress