how much oil u supose to add on an oil change , l own a passat 02 v6, and l add 5qt but it seems to be low still

6 quarts, sometimes a little more depending on how long you drained it.

If you look in the owners manual it should tell you the oil capacity granted you will actually need a little less due to not every drop of oil draining from the engine. Also less oil is needed if you do not change the filter (which in my opinion is the more important part of the oil change)