New Delhi, Oct 5 (IANS) Superstar Rajnikanth rocked the box office down south with 'Endhiran', but the Hindi version of the mega budget sci-fi outing 'Robot' lost out to Bollywood heartthrob Ranbir Kapoor's mushy antics in 'Anjaana Anjaani' in the northern region, where audiences are opting for the young romance saga.