If we want co compare grand movie with Amitabh
Ghajini in 2008 had better opening than what Veer had in 2010. That was last period movie on Salman.
Even before ToH, last period movie of Aamir, Mangal pandey broke opening record, while SRK with Asoka and Salman with Veer failed to do so.
So Aamir could've done it even without Amitabh. If wom would be good, TOH may have crossed even 55 Crore.
Amitabh factor has be negated by director Victor, on opposite PRDP had Barjatya, so big director also contributed to collections