Sehmat is seen burying her father.But in Islam women aren't allowed to be near where a dead person is being buried.
Alia Bhatt's mother is seen wearing Sindoor/Kumkum when Alia is getting married. This is a Hindu tradition and Alia's family is Muslim in the movie.
In climax, after the bomb blast in which Vicky Kausal was killed, Alia Bhatt reached the hide-out of Indian raw officers in Burqua. How can she reach that hideout without knowing its address. No where in the movie it was mention that she knew anything about the hide-out. She was always asked to contact them back in India only through secured codes.
While exchanging currency with the florist for the duplicate key, the currency note she was holding looks like 5 Pakistani rupees of that era, however there was no numerical "5" suppose to be beside the watermark circle of that note.
The plot of the movie is set in the year 1971. However, one of the scenes shows use of a silver Mercedes Benz w123 model. This model was only produced by Mercedes Benz in the year 1976, 5 years later.
A prochronism. The clothes and their design worn by people on screen seems more contemporary than of 1971 pre Elvis era.
The lead character is seen using a Beretta 92 for shooting practice, which is not possible as the story is set in 1970-71 and the 92 model entered production in 1976.
A quartz clock is seen in the Navy-Intelligence meeting. Even the first experimental quartz clock was made in '20s, these were not regular merchandises till early-mid-80s.