The actor stated that it is was quite disheartening for the team as it is an important movie and that the look was supposed to be released officially.
"Ideally they (pictures) should not leak. It's an important film. We would have liked to present the character in a particular time in a particular way, which we will still do. If it wouldn't have leaked it would've been better. There's nothing we can do about it now," Aamir said in an interview.
"Everyone has a camera today, so how much will you control? Even in 'PK', my 'ghagra' look was out on the first day of shoot. We have to deal with it, that's the reality," he added.
Aamir said the team has been given strict instructions to not click pictures on the sets.
"We try to keep it as secret as possible. Normally, on shoots when fans come to meet me, I click a picture. But not during 'Thugs...' because the fan will put the picture on social media.
"None of us are allowed to click photos in the get up. We take all these precautions."
This is the first time Aamir will be seen working with Big B and the "Dangal" star is "really enjoying working with him as he is an amazing actor."
Aamir said, growing up, it was a magical experience to watch the 74-year-old actor's movies.
"It was an amazing experience watching Bachchan sir in the cinema halls. His aura and powerhouse performances were magical. He had a complete hold on us as an entertainer. The sway that Bachchan had, I don't think it can be recreated.
"He had seven films running simultaneously in theatres. He used to clash with himself. That was a different era. The stardom which Mr Bachchan has seen, none of us will ever see."
The actor is currently gearing up for the release of his production, "Secret Superstar".