The joint session of the two Houses of Parliament is convened when a bill passed by one House is rejected by the other House (option 2) or when taxes approved by one House are rejected by the other House (option 3). In these cases, a joint session is called to resolve the deadlock and find a solution. The purpose of the joint session is to bring both Houses together and allow for a discussion and debate on the issue at hand. During the joint session, members from both Houses have the opportunity to express their views and vote on the matter. The decision taken in the joint session is considered final and binding. However, it is important to note that the joint session is not convened in case of a national emergency (option 1), as this is a separate situation that requires different procedures.