If it is 6K and 2002 then it is definitely a mk3. However, I have dealt with parts suppliers previously who refer to the mk2 as the mk1, completely ignoring the pre-VAG cars, so just knowing what model you own is not necessarily going to avoid future confusion. My advice is to quote the chassis number, although I realise this is not always possible.
I have mk2 Ibizas with a number of mk3 parts fitted, so I share your pain