Stupid computer question

Can I put both my rtx 2060 super and rx 5600xt on same motherboard and mine salad?

Yup, assuming the motherboard has two PCIe 16x slots, with enough space between eachother.
Should also make sure that your PSU has enough PCIe connectors / can safely supply the peak wattage your system may draw.
Whether you are able to mine with both shouldn’t be a concern, as Salad should be using PhoenixMiner for that - which supports both AMD and NVIDIA cards.

Ok so their would be no driver error or what ever?

I’m not too sure about the drivers side of things - Though, NVIDIA and AMD cards have defo been mixed together before, so I’d assume it will work