An ATBB is going to be very difficult right now for any actor to achieve. A film would need more than 400cr to get this, and this is approx 2.8-3cr footfalls.
Considering the last film to cross 3cr was TZH, Sanju fell just short of 3cr and last year Kabir Singh was the most watched film with 2.5cr (approx). Even War with the large scale and canvas couldn't touch 3cr footfalls, it is going to be very difficult for any film to achieve such figures.
400cr will definitely be achieved, but that would be when ATP is around Rs. 190 (currently between 155-160).
Next bet would be LSC for sure. And if the Hirani-SRK film goes on floors, it might get the ATBB.
Of course, that depends on what the criteria for an ATBB is and what the criteria for Super Blockbuster.