The film's crew were shooting in Haryana from over two months.
"75 days of shoot over @SultanTheMovie, last 30 days left... Feels like just started shooting. Time flies," Zafar posted on Twitter.
The movie will see Salman playing Sultan Ali Khan, a Haryana-based wrestler.
The sports drama, set to release this Eid, will have a box office clash with Shah Rukh Khan's "Raees".