While I support Ukraine, I see no reason for Thailand to get involved and condemn Russia.
It's not diplomatically necessary or of much benefit to Thailand, or Ukraine.
In any case, Thailand can't point the finger at Russia, as both have a corrupt oligarchy, buying up football teams and UK assets, dodgy elections, a fake democracy, even a Crimean style historical and questionable land grab of Malaysia, which is the cause of the southern troubles, and lastly, they're both doing military conscription.
Even the flags are similar! ????????????