The lunchbox, stolen last week, was recovered along with a ruby and gold teacup, saucer and teaspoon.
Two men from the southern city of Hyderabad have been arrested.
The items, valued at $7m (£5.4m), once belonged to Mir Osman Ali Khan, the last Nizam (king) of Hyderabad and once the richest man in the world.
Police allege the two men had fled to the western city of Mumbai in the hopes of finding a buyer for the stolen goods where they lived a "fancy life" in a five-star hotel for a few days.
However, they were unable to find a buyer and returned to Hyderabad where they were arrested after a massive manhunt.
Officers had initially struggled to identify the robbers because they had turned off all 32 CCTV camera's in the Nizam's palace.
However, a camera near the palace captured the two men on a motorbike. Police say they found the motorbike a few days later and that helped them identify the pair.
The recovered items will be handed over to the Nizam Museum, which opened to the public in 2000. Its collection comprises expensive gifts given to Mir Osman Ali Khan in 1937.
Khan ruled what was then India's largest princely state. He died in 1967.
His fabled wealth included the world-famous Jacob's Diamond - which was the size of an egg - and many other pieces of exquisite jewellery.