Jee advanced examination is the qualifying examination to get seat in IIT. Students are eligible for JEE advanced only if we get qualified in the first examination that is known as JEE mains. JEE mains is the easiest examination when compared to JEE advanced as JEE advance has high difficulty level of JEE mains.

So JEE mains is the first paper and only first 245000 students of JEE main get qualified for JEE advanced