Is it true that number of students opting out of IIT after taking admission has grown over the years? If yes, that what can be the cause?

Yes, to a certain extent. It has been reported that up to 4400 students have left the prestigious IITs and NITs in the last three years, and academic stress has been identified as one of the causes of this situation. Around 2060 students left the IITs (Indian Institutes of Technology) alone between

Yes, somewhat it's true, it was reported that as many as 4400 dropped out of the premier IITs and NITs in the last three years and academic stress was found to be one of the reasons for this situation. From the year 2012-15, around 2060 students dropped out of IITs (Indian Institutes of Technology)