Some of the Census 2001 data are in microsoft access files (having filename extensions .mdb). A microsoft access file can have several tables inside, each of which contains data. There is a software called mdbtools that can be used to read access files.
The command mdb-tables can be used to see the names of tables and the command mdb-export can be used to export access tables to csv files. Use and to see the manual pages.
If mdbtools is not installed on your machine you can use it from the server. Go to the server using ssh (ssh -X [email protected]) and then extract the file using mdb-tables and mdb-export.