$ sudo apt-get update
$ sudo apt-get install gcc-multilib-mips64el-linux-gn

gcc-multilib-mips64el-linux-gn is installed in your system.

Make ensure the gcc-multilib-mips64el-linux-gn package were installed using the commands given below,

$ sudo dpkg-query -l | grep gcc-multilib-mips64el-linux-gn*

You will get with gcc-multilib-mips64el-linux-gn package name, version, architecture and description in a table

gcc-multilib-mips64el-linux-gn package basic information: