In Console mode, the scrollbar is a console feature, not a Vim
feature. But Vim will tell you at which "percentage" of the file you
are looking, usually in the bottom-right corner of the current
split-window, where it says one of the following:
All
Top
Bot
nn%
The first three tell you that you see one end, or the other, or both,
of the file, Otherwise it tells you a percentage, from 01% to 99%,
meaning you are at that "percentage point" within the file. If you use
a custom 'statusline' setting, it is the %P element (or you can use %p
instead, for more verbosity).
To get a Vim scrollbar, use gvim (or, on the Mac, macvim) instead of
vim. Then you can set 'guioptions' to have or not have scrollbars on
the left, right and/or bottom depending on some conditions (see ":help
'guioptions' " with the single quotes but not the double quotes).
Best regards,
Tony.