By default % (in normal mode) should jump to the closing/opening brace or bracket when your cursor is on a brace or bracket.
So you could manually try out to find where it is, but it can be rather inefficient if the file is big.
Don't forget that with /(
and then n you should be able to quickly jump from brace to brace.
Vim should have a default tcl syntax file installed by default, so if it not already the case, you should add in your .vimrc
syntax on
filetype plugin indent on