If you have free electricity or free power source mining for you is profitable and it depends on what mining machine you have because if you mine coins with GPU the ROI will take years before you reach the ROI. But if you are mining with ASIC miner I think you can reach the ROI fast.
if we exclude bitcoin from the list then it depends on timing. there are years (like this year) that altcoins are dumping hard and everyone loses money even miners so they will have a much harder time reaching profit let alone ROI. of course with no electricity cost it will be better but not by a lot.
then there are years when we have lots of altcoin pumps like 2017 or 2013,... and mining coins, specially the GPU coins (since they are pumped a lot more) is more profitable than coins that are big enough to have an ASIC.