Varies highly with the difficulty level of question paper and other factors. Generally,  for the moderate level of difficulty, it is around 70-75 for external students and around 60-65 for internal students. It can come down to even 50 marks for external students and 40 for internal students for a difficult paper coupled with other factors such as late and deferred counseling process as in 2014. 
My advice to you would, however, be, to concentrate more on your preparations and give your best shot. Don't prepare with a preset target score as it can deceive you into making a wrong decision at your test date. All the best!