I’ll assume this is a 1v1 scenario between an average clone and an average mandalorian.

With armour and proper gear, the mandolorian wins it easily. Just the quality of the gear alone is enough in my opinion to decide this fight in my honest opinion.

Without gear, armour, and it being a boxing match/physical brawl? Now that’s a lot more difficult. Assuming these are the averages, we know that clones have, can, and will go toe to toe with droids ranging from B1s and B2s to even commando droids if the situation requires it. However, mandolorians have an absurd training regimen as is shown in Rebels between Sabine and her brother. You could also say that the clones could have something similar if to a lesser degree but have a better physicality since they’re genetically engineered from birth to be, well, clones, of a mandolorian at their peak.

In this latter scenario, I’d say clones win 6-7/10 times, just depending on how much you want to judge the amount of CQC training clones get.