Don't know what the average age is to enter the world of boxing but Hari has always had good hands, footwork and he turned 27 in December.
Usually you start as an amateur in your youth/adolescence
Vladimir Klitschko started boxing at age 14, winning the gold medal at the Olympics 1996 at age 20, becoming pro the same year.
Mike Tyson won the gold medal at the Junior Olympics at age 16 and became (the youngest) pro world champ at age 20.
Muhammad Ali won the gold medal at the Olympics at age 18 and became pro the same year. World champ at age 22.
Joe Frazier won the gold medal at the Olympics at age 20, became pro the same year. WBA & WBC champ at 26.
Lennox Lewis won Olympic gold at 23. WBC champ at 27.
I'm not saying Hari won't have success in boxing, but starting at 27 without "real" boxing background is pretty late. He has not only to adapt his technical boxing, but also his strategic approach due to the higher number of rounds. These two things are what most kickboxers struggle with. In particular completely shutting down your reflexes to use your kicks is quite hard and in the process of getting rid of the kicking reflexes, your boxing is slowed down, because your brain has the choice of kicking and boxing and has to chose against kicking. That decision making takes split seconds which a pure boxer doesn't need. And boxing is even more about "building up" a fighter than MMA and a single loss is more of an obstacle to your career than in Kickboxing or MMA. So while it's not impossible that Hari has success, it will be very hard for him.