Under the pressure of the Viceroy, in November 1947, the Nizam signed the Standstill Agreement with India, according to which the post office, telegraph, rail, road traffic and trade between India and Hyderabad would continue smoothly, but the Nizam, joining the Union of India. Keep putting off the matter. Along with this, he also encouraged the fanatical communal Muslim Razakars in his state.
The Nizam assured the Razakars that when we rebel, our English friends will help us. Seeing the support of the Nizam, the Muslim communal organization Itidad-ul-Muslimeen and its para-military Razakars started intimidating and plundering the majority of the Hindus of the princely state of Hyderabad so that they could leave the state and run away. Violent acts of Razakars disturbed the peace and order in the princely state.
The railways and roads passing through the princely state of Hyderabad were damaged and Hindus traveling by trains and buses were looted. This made the situation very bad.
Qasim Rizvi, the leader of the Muslim Razakars, threatened the Indian government that he would conquer the whole of India and hoist the Nizam's Asafzahi flag at the Red Fort in Delhi. After this mass killings of Hindus started in Hyderabad State and their property was looted or destroyed.
Mountbatten, Sardar Patel and VP Menon tried to convince the Nizam but now the situation was not even under his control. Razakars and fanatical mullahs-maulvis were instigating the Muslim masses and causing communal riots. Sardar Patel and VP Menon remained silent until Mountbatten returned to England.
In September 1948, two months after Mountbatten returned in June 1948, the Nizam announced that he was ready to accept the Mountbatten plan. On this, on 13 September 1948, Patel replied- 'It is too late now. The Mountbatten plan has gone home. At that time Nehru was on a tour of Europe and Sardar Patel was acting as the acting Prime Minister.
Therefore he ordered the army to integrate Hyderabad into India on the same day. This operation was named Operation Polo. The Indian army under the leadership of Major General Joyntonath Choudhary entered Hyderabad. In five days of action, the Indian army crushed the resistance of the Muslim Razakars. Thousands of Razakars were killed. The bodies of the Razakars were seen lying all over Hyderabad. On 17 September 1948, the General of Hyderabad, General E.I. Edrus surrendered to General Choudhury at Secunderabad. Thus Hyderabad was merged with India in just 5 days of police action.
No bomb went off, no revolution took place, as was being feared. On 18 September, Major General Choudhury took over as the military governor of the princely state of Hyderabad. The princely state of Hyderabad was included in the Indian Union. The Nizam was forced to accept the new system.
Sardar Patel treated her with respect. He was allowed to remain the honorary head of the princely state. Later, when the states were reorganized, the princely state of Hyderabad was broken up and its territories were merged into the provinces of Andhra Pradesh, Karnataka and Maharashtra.