Do product base companies hire freshers directly who have five star or seven star ranking on Codechef or Hackerrank ?

You’re missing the whole point of why companies conduct interview. They want to see if their candidates fit their company culture. Competitive programmers do have a big fat chance of getting in. At least they don’t have to worry about technical/coding interviews, but in the end, it’s all about how they present themselves. Nobody wants to hire a snob.