Unless the rules and regulations of your building indicate otherwise, yes, you may use a BBQ on your balcony.  

Make sure the BBQ: 

• is used more than 600 mm (24 inches) away from a door or window 
• is never located less than 450 mm (18 inches) away from all combustible materials
• is never located between a door and a stairway
• is not a nuisance (doesn't give off any sparks, soot or smoke that dirties or damages the neighbours' properties nor bothers the neighbourhood) 

If your balcony is made out of a combustible material and if you use briquettes to operate your small BBQ: 

• Make sure you place it on a sheet metal plate more than 600 mm (24 inches) all around the appliance.

If you use a propane BBQ, remember that propane tanks: 

• are prohibited inside a building or in a closed space 
• must be kept in the open air 
• must not be used for more than ten years  
• must not be tossed in the garbage (but rather brought to a propane distributor)