What is the full form of IIT entrance exam?

There isn't one single "IIT entrance exam." The Indian Institutes of Technology (IITs) use several entrance examinations, depending on the program and level of study. The most common and well-known is the Joint Entrance Examination (JEE), which has two main parts:

* JEE Main: This is the first stage of the entrance exam. It's a qualifying exam for JEE Advanced.

* JEE Advanced: This is the second stage and is only for students who qualify JEE Main. It's used for admission to the IITs.

So, while there's no single full form encompassing all IIT entrance exams, JEE (Joint Entrance Examination) is the most accurate and widely understood answer.