download ROOT v6.06.04 source
https://root.cern.ch/download/root_v6.06.04.source.tar.gz

md5: 55a2f98dd4cea79c9c4e32407c2d6d17
sha1: aff5cf3e3380821c97ac7047bac6341f1e7811d1
sha512: b33a8f71322c5bf5984dfb6db38ff99e328845850e2c850f8090b18e30cf02ab62a4ff0bd930b6a8a5e0e8abb6e4893c3a11b033cdb347932581d8c7670ca67e

extract

tar xvf root_v6.06.04.source.tar.gz

alternative

git clone http://root.cern.ch/git/root.git
cd root
git tag -l
git checkout -b v6-06-04 v6-06-04

install dependencies (https://root.cern.ch/build-prerequisites)

apt install libXft-dev

compile

cd root-6.06.04/build/
cmake ..
make -j8
make install

use root

source root-6.06.04/bin/thisroot.sh
export ROOTSYS=/path/to/root-6.06.04/
root -l

new TBrowser
.q