Can i run Catalina?

Mojave was never said to not be compatible with a 2010-2012 Mac Pro. It did require the video card, but Apple acknowledged this, and even provided a list of compatible video cards for it. Install macOS 10.14 Mojave on Mac Pro (Mid 2010) and Mac Pro (Mid 2012) - Apple Support

Catalina is explicitly said to not be compatible with any Mac Pro except the 2013 and currently unreleased 2019 model.

No. Catalina requires a 2013 or later Mac Pro: macOS Catalina - Compatibility - Apple

At this writing Apple is not officially supporting Catalina or Catalina BETA on the Mac Pro 2010-2012 models.

This appears to be due to a newer subtler variation of a cache-stealing vulnerability (similar to Meltdown) recently discovered by researchers.

Intel has declined to update the microcode, deeming the entire processor family "too old". Mac Pro 2010-2012 owners are unhappy about this.