Assertion(A): Daulatabad fortess was besieged by the Mughal forces in the year 1631 and it had to be surrendered to them. Reason (R) : Malik Ambar betrayed his Sultan during the siege of Daulatabad fortress by Mughal forces.

Assertion (A) is true as the Daulatabad fortress was indeed besieged by Mughal forces under Mahabat Khan during the reign of Shah Jahan. While some sources date the final capture to 1633 CE [t1], the campaign and siege operations were active in the early 1630s (1631-1633) following the Mughal push into Ahmadnagar [c1]. Reason (R) is false because Malik Ambar, the famous regent of the Nizam Shahi dynasty, died in 1626, several years before the final siege and surrender of Daulatabad [t3][t8]. Far from betraying his Sultan, Malik Ambar was the primary architect of resistance against Mughal expansion in the Deccan, famously defeating them at the Battle of Bhatavadi in 1624 [t3]. The eventual surrender of the fort in 1633 was due to the efforts of Mahabat Khan and the internal decay of the Ahmadnagar sultanate after Ambar's death.

Sources

1. [1] http://indianculture.gov.in/forts-of-india/discovering-the-forts-of-india/daulatabad-fort-abode-wealth-and-power
2. [2] History , class XI (Tamilnadu state board 2024 ed.) > Chapter 14: The Mughal Empire > Deccan Sultanates > p. 209
3. [3] https://ia801209.us.archive.org/22/items/in.ernet.dli.2015.533706/2015.533706.life-and_text.pdf