Explanation:

- Jagat Singh: He ruled the Nurpur princely state from 1613 to 1646. Under his reign, the Mughals, led by Emperor Shah Jahan, captured several forts, including Maukot, Nurpur, and Taragarh. He eventually accepted Mughal suzerainty.

- Rajrup Singh: Not much is known about this ruler in relation to significant Mughal confrontations over fort captures in this context.

- Bir Singh: Does not have a well-documented history of losing forts to the Mughals during his reign.

- Jaswant Singh: Like Rajrup Singh and Bir Singh, there is no specific association with the capture of these forts by the Mughals.

Correct Answer: Jagat Singh