Mandala Fort was built by

The Garha-Mandla kingdom, ruled by a succession of Gond dynasty kings in the Mahakoshal region of present-day Madhya Pradesh, spanned several centuries. Each ruler in this line is associated with specific monuments and events from their own era, so a structure at Mandla must be attributed to the particular ruler under whom it was built, not to the dynasty as a whole.

Mandla Fort (Mandla Durg), built on the banks of the Narmada river, was constructed by Narendra Shah, a 17th-century Gond ruler of Garha-Mandla, after Gond authority over the region had been restored under Mughal suzerainty. The fort complex includes structures such as the Shah Burj, the Satkhanda Mahal, and the Raj-Rajeshwari Devi temple, and Mandla became the dynasty's capital seat under his rule.

This can be cross-checked against the other Garha-Mandla rulers named among the options, none of whom fits the same 17th-century, Narmada-side construction:

• Sangram Shah (reigned c. 1480-1531) preceded Narendra Shah by more than a century; he is remembered for expanding the kingdom and for holding fifty-two forts ('bawan garh'), not for the Mandla structure.

• Dalpat Shah, son of Sangram Shah, ruled in the mid-16th century and died young, before Rani Durgavati's regency began.

• Shankar Shah belonged to a much later, 19th-century generation of the family and is remembered for his execution during the 1857 uprising, well after Mandla Fort already existed.

Since only Narendra Shah's reign aligns with the fort's 17th-century construction on the Narmada, the correct answer is Narendra Shah.