Your gearbox is tiptronic ? ( 6 speed )
If so you have zf6hp19a . There are 2 types of oil depending of gearbox software , zf lifeguard 6 and zf lifeguard 8
If you go to audi they will tell you the tranny is " sealed for life " and they wont change oil but they will sell you correct oil+filter by vin number. Get zf oem oil
Zf who made these gearboxes recomend oil change every 90k.
Also there is a procedure to change oil in them so you need to find a good garage. Its good to do a flush firts so any metal shavings will be removed as they will kill your tranny
Hope this helps as i spend a year looking in to this :) .