Dear Vaibhav, every exam has 4 different set of question papers. Like AA,BB,CC,DD for NEET. These are called Paper codes. Other exams like GATE have different paper codes. This means that every question paper has different set of questions. Sometimes jumbled in the sequence and sometimes with a twisted question for the same answer. Every student ideally doesnt get a different question paper as only 4 sets are prepared. Say if there are 16 candidates in an examination hall sitting behind each other, 1st person gets AA, 2nd person gets BB, 3rd person gets CC and 4th person gets DD.Not exactly in the same order. This has been starte nitially to stop malpractices of the candidates. The question paper you get may be different from the one your friend who is sitting next to you or behind you gets. It is important to mention your paper code in the OMR and you also will get a different Answer key released for every different set of question paper.