How to check penalised or banned websites ?

Hlo Friends,
Can anyone tell me, How to check penalised or banned websites ?

Look for webmaster for message for google, Check your traffic if there is sudden dip, check you keywords ranking is there is sudden dip in there in ranking, if the answers is yes then, there might be chances you got penalise by google

you can check your main keywords. If you see your site go down on search results, it mean your site is penalised by Google. Sometimes, you can see announce messages from google at google search console.

Use webmaster tool

You can use webmaster tools for it or check its ranking in serps, if it goes down then your site is affected by search engine.