Two characters refer to a saying that one Indian rupee is five Bhutanese rupees. The exchange rate of the Bhutanese currency, the Ngultrum, is one Indian rupee, not five. If the saying is about purchasing power, it is an exaggeration: numbeo.com estimates the cost of living in Bhutan's capital is about 75% that of Mumbai.
When Saajan works in the canteen on behalf of Shaikh he has a green marker in his hand, but when the camera changes it turns into red. In the same scene Saajan holds a red marker but when the camera changes it turns into a pen.
When Saajan received the lunch box for the first time there were four compartments in it. He opens only three compartments of the lunch box, but when the camera changes it can be seen the whole lunch box is open.
After his marriage, Shaikh tells Saajan that on their first train ride together he got into the first class compartment without a ticket. However, during their first ride the train seat seen is that of the second class.