documentclass{article}
usepackage{fontspec}
usepackage{unicode-math}
% setmathfont{texgyretermes-math.otf}
setmathfont[Kerning=On]{TeXRygeTermesMath-Regular.otf}%%% same as Tex Gyre Termes Math, with an attempt to improve kerning
begin{document}
({f})
[
  {f}
]
end{document}