How to install i386 packages on Ubuntu on ARM-based Nexus 7?
You can't install a i386 package on ARM, but it is very well possible that an ARM alternative exists or if source code is available you might be able to compile from sources.
Like others have said, the i386 package likely won't run, but if you want to install it anyway, you can run
sudo dpkg --force-architecture -i /path/to/package.deb