Hi Roja Gutha,
Firstly you must clarify which type of exam you are pursuing? While talking about some of the government exams, the exam is categorized into two or three phases. Phase 1 is mainly the pre-level exam. In this phase, students appear and obtain a total score. The exam governing body releases a cut-off and those candidates who secure marks more than the cutoff are called for phase 2. Phase 2 is the main level of the exam and selected candidates then appear for phase 2. This process is similar to phase 3 and so on.
While in some exam, if the number of candidates appearing are more, then the level of the exam is organized in different phases. For example, if the appearing candidate is huge in number then a pre-exam can be conducted in 2 or more phases and questions will be for different phases. You don't have any choice in terms of giving exams in different phases. The governing authority will provide an admit card and you have to give the exam at the given time and phase.
Hope this helps you. I could give you an accurate answer if you have given the exam name.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile