Karan Johar claims he was inspired to do a thriller instead of his usual family film by Aditya Chopra, who had broken Yash Raj Films out of their romantic film mold by doing the action film Dhoom (2004). He paid tribute to Chopra by casting that film's stars, John Abraham and Esha Deol.
Nana Patekar was originally offered the role of Kali Pratap Singh. Along with him were Saif Ali Khan and 'Shahid Kapoor' who were had a mixed feeling when offered.
There is a sheet of paper on which the national park's rules are printed. One of the park officers states that those are in English on the front and in Hindi on the back. However, there are several other shots in which it is plain that the back of the sheets is blank.