The number on the sidewall provides information on the maximum weight capability for the tyre. There are quite a lot of different T6 models, so I'd recommend checking the vehicle's handbook to see the specific load rating(s) for the T32 Kombi. We'd aim to buy tyres that provide more car-like handling, as this matches your usage of the van. Something like Michelin Agilis 51 might work or Continental Vancos. However, given that these tyres are designed with an emphasis on handling, they might wear out quicker than the heavy duty tyres your van is running on at the moment.