Joint sitting is an extraordinary machinery provided by the Constitution to resolve a deadlock between the two Houses over the passage of a bill. A deadlock is deemed to have taken place under any one of the following three situations after a bill has been passed by one House and transmitted to the other House:
In reckoning the period of six months, no account can be taken of any period during which the other House (to which the bill has been sent) is prorogued or adjourned for more than four consecutive days.
If the bill (under dispute) has already lapsed due to the dissolution of the Lok Sabha, no joint sitting can be summoned. But, the joint sitting can be held if the Lok Sabha is dissolved after the President has notified his intention to summon such a sitting (as the bill does not lapse in this case). After the President notifies his intention to summon a joint sitting of the two Houses, none of the Houses can proceed further with the bill.
The Speaker of Lok Sabha presides over a joint sitting of the two Houses and the Deputy Speaker, in his absence. If the Deputy Speaker is also absent from a joint sitting, the Deputy Chairman of Rajya Sabha presides. If he is also absent, such other person as may be determined by the members present at the joint sitting, presides over the meeting. It is clear that the Chairman of Rajya Sabha does not preside over a joint sitting as he is not a member of either House of Parliament.
The quorum to constitute a joint sitting is one-tenth of the total number of members of the two Houses. The joint sitting is governed by the Rules of Procedure of Lok Sabha and not of Rajya Sabha.
If the bill in dispute is passed by a majority of the total number of members of both the Houses present and voting in the joint sitting, the bill is deemed to have been passed by both the Houses. Normally, the Lok Sabha with greater number wins the battle in a joint sitting.
The Constitution has specified that at a joint sitting, new amendments to the bill cannot be proposed except in two cases: