antlr-tab-offset-alist

antlr-tab-offset-alist is a variable defined in `antlr-mode.el'.
Its value is

((antlr-mode nil 4 nil) (java-mode "antlr" 4 nil))

Documentation:
Alist to determine whether to use ANTLR's convention for TABs.
Each element looks like (MAJOR-MODE REGEXP TAB-WIDTH INDENT-TABS-MODE).
The first element whose MAJOR-MODE is nil or equal to `major-mode' and
whose REGEXP is nil or matches variable `buffer-file-name' is used to
set `tab-width' and `indent-tabs-mode'. This is useful to support both
ANTLR's and Java's indentation styles. Used by `antlr-set-tabs'.

You can customize this variable.