I can install gnome desktop and use it on rock pi 4?

I can install gnome desktop and use it on rock pi 4?

Absolutely. Gnome is the most popular DE but not for ARM boards since it’s a power hog, resources wise, you can still install gnome on RockPi4:

https://wiki.radxa.com/Rockpi4/downloads

You install ubuntu server 20.04 and then install gnome manually:

https://linuxconfig.org/how-to-install-gnome-on-ubuntu-20-04-lts-focal-fossa

Aditionally, you can also install Manjaro Gnome on RockPi4 using manjaro-arm-installer:

Gnome desktop works perfectly with Armbian