Who were the Delhi sultans ? How many were ruled there ? Please answer me

Dear student,
The answer to your question is given below:

1. The Delhi Sultanate was established by the Central Asian Turkish warlords. 
2. The Delhi Sultanate lasted in India from 1206 to 1526 AD. 
3. They were called the Delhi Sultans because they made Delhi as their capital.

 
Five dynasties ruled over Delhi :  

1. Mamluk dynasty (1206–90)
2. Khalji dynasty (1290–1320)
3. Tughlaq dynasty (1320–1414)
4. Sayyid dynasty (1414–51)
5. Lodi dynasty (1451–1526)

Some prominent Delhi sultans were Illtutmish,  Alauddin khiljai and Sikander Lodi. 

Regards,