He needn't prove anything. He is right there at number 5 behind Khans and Akshay Kumar. It is only his experimenting nature which cost him openings else see his last 5 films universal films.
ADHM : ₹13cr Pre Diwali & Clash (almost equal to ₹20cr on a Normal day and solo)
Besharam : 2nd Highest Non Khan Opening with Bulk of Pre Release Negativity
YJHD : Highest Non Holiday Opening and Weekend
Rockstar : Again near ₹10cr Opening, only 4th time a Non Khan film to had so if I get it right (2 out of these were RK starrer)
Rajneeti : 2nd & Highest Non Khan ₹10cr Opener
Even consider opening of films like Tamasha and Jagga Jasoos. None of Varun and Ranveer is capable of doing so.
Now regarding Hrithik. Well I take both as same. Ranbir leads Hrithik clearly in North while in South barring AP/Nizam both can be same. Now in Mumbai, CP, CI, Bihar and West Bengal it's about what sort of film is as both are not a big force (barring Mumbai in these).