Ans. According to me , it is not necessary for any Indian to leave India after the partition in 1947 because as we all know that India is a huge diverse country with lots of secular states and territories which means that it was totally up to the citizens of the country 
whether they want to migrate in Pakistan or should continue living in India . As per the sources , post partition massive population exchange occurred between the two countries. Indian Muslims were under fear of losing their country and to settle down in the other strange country without much resources and funds . As from many years , they have been living in the same land which provided them shelter , comfort and security . So , it was the matter of their life whether they should put it into risk or not .

In  September 1947 , Muslim refugees are seen on 
the top of a train leaving New Delhi for Pakistan . However, the Census failed to identify those Muslims who have been migrated from India to Pakistan . As there was Amritsar Massacre going on that time in 1947 which led an attack on the Indian refugees and 
over 3000 refugees were killed and 1000 were wounded . This situation created a havoc and thousands of Muslims were fleeing away from India in order to rescue their lives . Across 14.5 million 
people crossed the borders for the safety of their religious minority .

But many of Muslims decided to leave Pakistan for a secular India as they were deeply inspired and influenced by our Indian freedom fighters like Gandhi ji  and other famous personalities like Pandit Nehru and Abdul Ghaffar Khan which led them to took a stand for 
their mother country post partition and gradually they shunned Jinnah’s Pakistan for Gandhi’s India . These personalities were Lala Ghulam Sarvar, the father of the then superstar Late Shri Dilip Kumar ; Taj Mohammad Khan , a political activist who was the 
member of the congress party and the father of the king of romance Shahrukh Khan . They sacrificed their homeland to reunite with the country which has a glorious history of having relevant important events of the past .

As I mentioned earlier , that many of the Muslims wanted to migrate to Pakistan but it was not practical for all of them to leave their homes all of a sudden and shift to an another country . Because this situation would be difficult for both of the countries 
to bear with massive migration and overpopulation . But in spite of all these factors , both the countries have to deal with some issues like Pakistan and India faced the crisis of providing shelters or land to their refugees , they also had a dispute over the sharing 
of river Indus and last but not the least , they had a problem with the accession of princely states . Since both the countries were newly separated , they had various riots amongst themselves over many issues but with time the same has been dissolved 
subsequently .

India stands tall in the world because of its image as a tolerant, modern and progressive country. But it has been shown that India wanted to damage its reputation and position by making these toxic policies of dividing the nation amongst different religious identities which is not true . As India , who had spent several of 
years to maintain a positive image of itself would not want to degrade it within a couple of days . It was the Britishers who had invented the two nation theory in order to spread hatred and divide the nation into two pieces because they were aware of the fact that Muslims had shed the equal amount of blood and sweat as compared to Indians in order to get independence from the colonial rule . So , they just wanted to break that trust and brotherhood between the religions by fueling the feeling of mistrust and hatred within citizens to make the country weak and 
divided .

Furthermore , in 1950 , an accord or agreement was signed between India’s Jawaharlal Nehru and Pakistan’s Liaquat Ali khan in order to secure its minorities to pledged to provide equality of 
citizenship regardless of their religion . As Jawaharlal Nehru and Mahatma Gandhi were not very happy with the massive migration , they promised to help their citizens and both sides promised to help their citizens to acquire looted property and to give assistance in the recovery of abducted women and also to not recognize conversions made during communal disturbances .
We all know that Pakistan was carved on the east side and the west side of India was up in the north direction. Therefore , it was not much difficult for the Muslims living in Punjab , Haryana , UP , Bihar , Bengal and Odisha to relocate themselves comparatively to 
the other parts of India where it was a matter of life and death as there were riots happening everywhere . So , it was a good idea to stay where you are whether of leaving your place after all you can start a new beginning anywhere irrespective of a particular place 
and make a better future of themselves in the New India . As there is a saying in Hindi “ जान हैतो जहान है”, meaning “ if you have life , you have the world “.

In 1947 , Muslim refugees evacuated from areas of unrest in New Delhi and queuing up for water at New Delhi's Old Fort in September 1947. This shows that 
all of the Indian Muslims were not happy with the idea of partition but according to the Muslims, it was necessary for both religious identities to separate their borders . For the Muslims , the Partition was necessary because it was felt, Hindus and Muslims cannot live together. This excerpt of Jinnah’s speech in 1940 summarizes it best:

                  “It is extremely difficult to appreciate why our Hindu friends fail to understand the real nature of Islam and Hinduism. They are not religions in the strict sense of the word, but are, in fact, different and distinct social orders; and it is a dream that the Hindus and Muslims can ever evolve a common nationality, and this misconception of one Indian nation has gone far beyond the limits and is the cause of more of our 
troubles and will lead India to destruction if we fail to revise our notions in time. The Hindus and Muslims belong to two different religious philosophies, social customs, and literatures . They neither intermarry nor inter-dine together, and indeed they belong to two different civilizations which are based mainly on conflicting ideas and conceptions. Their 
aspects of life, and of life, are different. It is quite clear that Hindus and Muslims derive their inspiration from different sources of history. They have different epics, their heroes are different and different episodes . Very often the hero of one is a foe of the other, and likewise, their victories and defeats overlap. To yoke together two such nations under a single state, one as a numerical minority and the other as a majority must lead to growing discontent, and final. Destruction of any fabric that may be so built up for the 
government of such a state.” 

There were some Muslims who feel that they were 
prosecuted in India as they were the supporters of Jinnah who thinks that the partition was necessary for them to get freedom and independence .They thought that were not getting enough space to worship and preach their religion .This feeling of inconvenience and possessiveness led many riots between the two religious communities and ended up on dividing the country during the end of the colonial rule in 
1947 .