centos 6 install protoc

#Download source code :
wget https://github.com/google/protobuf/releases/download/v2.6.1/protobuf-2.6.1.tar.gz

#Extract :
tar -xzvf protobuf-2.6.1.tar.gz

#Build and install:

cd protobuf-2.6.1
./configure --prefix=/home/your/home/dir/
make
sudo make install