India became a part of Islamic world? How rulers who had faith in Islam, maintained balance with their subjects? 

Arab merchants frequently came along the parts of western coast in the first millennium C.E. During the same period, people from Central Asialcaroe in subcontinent and settled in the north-western parts. With the advent of Islam and from the 7th century onwards, these regions became a part of that world which is often termed as the Islamic world.

Establishment of Islamic Authority : In 711 AD, an Arab General Muhammad Bin Qasim conquered Sindh and annexed to the domains of Caliph Later on (around 13th century) Turks and Afghans established Delhi Sultanate. Gradually, Sultanatfi spread in Deccan and other parts of subcontinent. Religion of most of the rulers in most of the regions was Islam. This situation remained till the establishment of

Mughal Empire in 16th century. Many regional kingdoms were emerged in the loth century and most of them had faith in Islam.

Maintaining balance with Subjects:

Theoretically, Muslim rulers were supposed to be guided by the ulamas. It was expected from ulamas that they could ensure that they ruled according to the Sharia. But the situation in subcontinent was so complicated because a large section of population did not subscribe to Islam.

In this context zimmi, means protected category, was developed. Zimmi word was used for the people who followed revealed scriptures like Jews and Christians living in the regions of Islamic rulers. These people paid a tax called Jizya. In lieu of that they gained the right of protection by Muslim rulers. Hindus in India were also included among zimmis. That’s why rulers like Mughals regarded themselves as emperors of Muslims and of all peoples.

Actually rulers generally adopted a fairly flexible policy towards their subjects. For example many rulers gave land grants and tax exemptions to Jainas, Hindus, Zoroastrians, Christians and Jewish religious institutions. They also expressed their respect toward non-Muslim religious leaders. These grants were given by many Mughal rulers including Akbar, Aurangzeb, etc.