Thanks Cathy for your reply.
I figure it out and then I realized that I don't need tDOM, because I'm using OpenACS 4.6.3. :)
I had to compile TCL (8.3.5) with --enable-threads and in unix/CONFIG file I added --with-tcl=/usr/local/src/tcl8.3.5/unix. From docs I thought that I must have --with-tcl=$aolsrc/... ;(
Also, you have to delete tDOM and unpack it again.
Thanks again for idea,