"No, it's not. Corona only look good if it don't put beside V-ray. "
well, from what and how you put things, it seems you yet lack some render or at least corona knowledge yet, so why not better ask for help if you have an issue?
that is normally better than making such statements right away. (the way you put it it comes more as a troll like comment. please note i am a user myself and not part of chaos)
there is a reason why many of the best archviz studios world wide use corona render as their first choice. it does have outstanding render and gi quality.
i have deep knowledge of both engines, (used vray probably as the first vray user on c4d) overall, and i love vray and corona as well. both are great, also in gi.
as you might know both are developed by the Chaosgroup team, they share their knowledge and technology.
Both use in fact pretty similar GI methods (like BF/LC), with only slight differences.
stronger differences are in the used render settings, the way materials settings work, ray depths etc., and even more in default vfb tone mapping settings.
what you see are the tone mapping differences that vray and corona have in their default settings. it seems also you have a not so well set leave material in the corona tree version. probably too high ior and too much transmission. vray in default is pure neutral, where corona has the today very common new ACIS style active as default , which many like, but can be too dark i agree, if used as full 1.0.
best share both scenes that we might be able to help you