$ sudo apt-get update
$ sudo apt-get install gcc-6-plugin-dev-mips64el-linu

gcc-6-plugin-dev-mips64el-linu is installed in your system.

Make ensure the gcc-6-plugin-dev-mips64el-linu package were installed using the commands given below,

$ sudo dpkg-query -l | grep gcc-6-plugin-dev-mips64el-linu*

You will get with gcc-6-plugin-dev-mips64el-linu package name, version, architecture and description in a table

gcc-6-plugin-dev-mips64el-linu package basic information: