How did the Muslim rulers of the Delhi Sultanate treat their Hindu subjects?
The Delhi Sultanate ruled varying areas of India for about 300 years starting in about 1206 AD. The rulers of the Sultanate were Muslim, but most of their subjects were Hindu.
So far as I know, the rulers treated their subjects pretty well. While some Hindus coverted and became Muslims, there was no policy requiring this. When subjects did convert to Islam, they brought some of their old beliefs with them and influenced Islam. The Hindu religion continued and was not really molested by the rulers.
As far as government goes, the sultans were somewhat more autocratic than previous rulers had been. But I have not seen anything that says they abused their subjects more than other rulers of the time.
The Delhi Sultanate encompassed several Muslim dynasties in north India from the thirteenth to early fifteenth centuries, when it fell to Babur and the emerging Mughal Empire. In temrs of religion the Muslim rulers were a minority ruling over a Hindu majority. As in other Islamic empires, there were provisions for dhimmi within the Delhi Sultanate. The dhimmi were non-Muslim subjects under Muslim rule. They were generally allowed to practice their religion in peace, so long as they accepted Muslim rule and paid a special tax called a jiziya. they were also barred from military service. Ostensibly, the reason for the tax was to pay for the protection they received under Muslim rule.
Delhi Sultanate refers to several different Muslim dynasties who ruled over substantial territories in Northern India, including what are now Pakistan and Bangladesh with Delhi as their Capital. The first in this sequence of Muslim rulers starting from 1006 was Qutub al-Din Aybak. The last one of the Delhi Sultanate was Ibrahim Lodi who was defeated by Babur in 1526.
The Stance of all Muslim rulers of Delhi Sultanate toward their Hindu subjects was not same. But essentially most of them were staunch Muslims and did not treat their Hindu subjects well. The Muslim rules often supported forcible conversion of Hindu's to Muslim religion. Other Hindus switched to Muslim religion to improve their economic position.
Some rulers destroyed and Looted Hindu temples. For example, Qutub al-Din Aybak is reputed to have destroyed over a thousand Hindu temples in holy city of Varanasi.