64 living Indo-European languages (around the outside), as well as many dead and extinct languages.
Moving into the image from the outside, we travel back in time, until we reach the core of the image, wherein lies Proto-Indo-European. Experts suppose that PIE was spoken somewhere around the border of Europe and Asia and diverged into the 10 inner Proto languages shown here 4500+ years ago (or maybe more).
There are about 380 Indo-European languages missing from this image. The Indo-Iranian branch is the largest, actually accounting for around two-thirds of Indo-European languages.