Alia is a very good actor, but best? I don\'t know. Possibly one of the 10 best actors in India.
Ranbir is above average though has not evolved much from his initial days ... his weaknesses get exposed when he shares frame with more competent artists (e.g. with Vicky Kaushal in Sanju). He is pretty good in certain type of roles ... someone edgy, disturbed, stressed, defeated, marginalised or physically challenged. Ranbir, I would say feature amongst the 50 good actors in India.