It looks like a Korean variety

This is a Aeonium that is looking for more light, the care is roughly the same as a Jade but they like a little more water

Crassula Lactea

It doesn't necessarily look like root rot to me, probably more of a fungal infection- I would probably hit it with a systemic antifungal using the manufacturer's recommendations. I like Bonide products

The leaves really look like a ovata but the purple screams Obliqua to me, like a reverted tri-color If you are a Facebook user, you could go to The jade plant exchange and then to the main page listed on the top in Russian, (the admins including myself all

Assuming you have watered regulary its likely suffering from root rot. I would recomend removing it from the pot to inspect the roots If they are rotten cut them off and then plant it in new dry cactus soil. Don't water for a while but mist it heavily every day. Hope this helps.

I like to use a multi pointed attack, Alcohol for topical treatment every other day for 10-12 days, Bonide Systemic in the top inch or so of soil, and a spray such as "Sevin" every 4 days or so, (not on the alcohol day) it seems to get them under control quickly...

Wow, that's a beauty! It looks like 'minor' or 'Crosby's compact' I would guess its at least 35 years old