Can cryptonight mine eth and etc?
Some crypto algorithms require less video memory to solve than others, but if an algo requires too little memory (e.g. - Bitcoin) then it is open to solving with custom-designed chips (ASICs) and GPUs are left in the dust at that point.
You can see how much video memory is required for some of the more popular Ethash* based coins here:
https://investoon.com/tools/dag_sizeNote that running Windows at the same time as mining - especially to play videos (e.g. - YouTube) - will require some video memory as well. During my brief test of Ethereum mining, MSI Afterburner (an overclocking and GPU monitoring utility) reported I was using just under 3GB on my 4GB GTX 1050 Ti, of which ~2.2GB was for Ethereum (the so-called "DAG file"). This means a 3GB GTX 1060 will be unable to mine Ethereum any day now (if not already)
However, when mining Ubiq I was using right around 2GB, so a 3GB card would have plenty of life left in it. Also, there are other coins which don't use a massive DAG file but which are still somewhat to fully resistant to ASIC attack, such as those that use the Equihash algorithm like Zcash, Zencash, Bitcoin Gold, Hush, etc. I am mining Zcash right now and MSI Afterburner is reporting around 993MB of video memory in use (once again, with some of that consumed by Windows).
However, with just 16 CUDA cores and 512MB of memory, I don't a GeForce 210 will be able to mine *anything*, even if booting into Linux or some other O/S that doesn't use a GUI.
* - Ethash is the name of the algorithm for mining (ie - solving) Ethereum and it is used for several other coins such as Ubiq, Expanse, Musicoin, etc.