A deadlock between the Lok Sabha and Rajya Sabha arises when both Houses of Parliament are unable to reach a consensus on a particular legislative proposal. In such a scenario, a joint sitting of the Parliament is called upon by the President of India under Article 108 of the Constitution to resolve the deadlock.

During the joint sitting, members from both the Lok Sabha and Rajya Sabha assemble together and vote on the legislative proposal. The decision of the joint sitting is determined by a simple majority of the total votes cast.

However, it is important to note that a joint sitting can be called only for the passage of ordinary legislation and constitutional amendment bills. Money bills are not subject to a deadlock between the two Houses as the Lok Sabha has the final say on them.