$ sudo apt-get update
$ sudo apt-get install gemrb-planescape-torment-data 

gemrb-planescape-torment-data is installed in your system.

Make ensure the gemrb-planescape-torment-data package were installed using the commands given below,

$ sudo dpkg-query -l | grep gemrb-planescape-torment-data *

You will get with gemrb-planescape-torment-data package name, version, architecture and description in a table

gemrb-planescape-torment-data package basic information: