/usr/lib/xgksfonts/I.gksfont is in libxgks2-data 2.6.1+dfsg.2-5.
This file is owned by root:root, with mode 0o644.
It is a symlink to /usr/lib/xgksfonts/./usr/lib/xgksfonts/6
/usr/lib/xgksfonts/./usr/lib/xgksfonts/6