I am an Indian citizen currently in Zurich having valid work/resident permit for 1 year (L Permit). I am planning to travel from Zurich to New Delhi via Brussels. Will I be requiring any transit visa in Brussels? It will just be a change of planes in Brussels.
If your long stay visa for Switzerland is valid, then you will not need a transit visa. Switzerland is a part of the Schengen Area and your flight from Zurich to Brussels will be Intra-Schengen. So you should be passing thru Schengen border control in Brussels.
If you are exhausting your visa on the last day, board the flight before your visa gets exhausted because the Zurich to Brussels leg will be considered "domestic" within the Schengen Area and you will atleast need a Uniform 'C' visa for it if your long stay visa expires.
Also note that the Schengen area does not issue transit visas anymore, only Uniform 'C' visas.