brother there is NO set standards for earning as a cardiologist. your earning depends on 3 factors these factor are:

Your Location: if you are A doctor you gives his services to urban area will have a higher income in compare to one who lives in sub-urban or rural areas

Your Experience: It is the most important and most delicate factor that decides your Income. As you can say with time you gain experience and that experience help to increase you income

3rd factor is that if you start your own clinic\hospital or you opt for a JOB

these three factor are on what a cardiologist income depends but on average a cardiologist can earn between 5.9-8.9 l.p.a. but for experienced doctors salaries may go as high 1.5-2.5 crore per year