Billon Tanka of Muhammad bin Tughluq

Obverse

Inscription	Zarb fi zaman Al-abd al-raji rahmat-allah Muhammad bin [Tughluq]	ज़र्ब फ़ी ज़मन अलअब्द अलराजी रहमतुल्लाह मुहम्मद बिन [तुग़लक़]	ضرب فی زمن العبد الراجی رحمۃ اللہ محمد بن تغلق
Translation	Struck during the time of the servant hoping for the mercy of God, Muhammad bin [Tughluq]	दास के परमेश्वर की दया की आशा के समय  प्रहार लगा, मुहम्मद बिन [तुग़लक़]	بندہ کے خدا کی بخشش کی توقع کے دوران ضرب لگا محمد بن تغلق

Reverse

Inscription	Al-sultan al-sayyid al-shahid Tughluq shah sannah salasin vasabaamiya	अलसुल्तान अलसाय्य्द अलशहीद तुग़लक़ शाह सनह सलसीन वसबामीया	السلطان السعید الشہید تغلق شاہ سنہ ثلثین وسبع مائۃ
Translation	The Sultan, The Fortunate, The Testifier, Tughlaq Shah (struck this coin in) the year thirty and seven hundred	सुल्तान, भाग्यशाली, धर्म के नाम पर जान देने वाला, तुग़लक़ शाह (इस सिक्के को बनाया) साल तीस और सात सौ	سلطان، خوش نصیب، مزہب کے نام پر جان دینے والا، تغلق شاہ (اس سکے کو بنایا) سال تیس اور سات سو

About

Muhammad bin Tughluq (1290 – 20 March 1351) was the eighteenth Sultan of Delhi. He was the eldest son of the founder of the Tughluq Dynasty, Ghiyasuddin Tughluq. He was a renowned innovator who was appropriately dubbed "Prince of Moneyers" for his contributions. He reportedly took a particular interest in the coin's design in addition to experimenting with various weight standards. Tughlaq created representational or token money in 1329, the year he relocated his capital to Daulatabad. These copper and brass-based coins could be exchanged for predetermined sums of gold and silver obtained from the Delhi Sultanate.

The fact that his efforts were a complete failure suggests that neither the benefits of his reform-oriented coinage nor how well they were sold to the locals, who were used to the metal's denomination being equal to the underlying melt value, were adequately communicated.

Although having representative currency is a good idea, it has one drawback: counterfeiting. There is a lot of benefit in creating forgeries because representational money has a very low intrinsic value and may really be swapped for precious commodities like gold or silver. Brass or copper Tughlaq's tanka could be exchanged for priceless gold or silver from the government, making it profitable for skilled forgers.

This particular coin is billon, so it is a part of Tughluq’s experiment. The coin itself weighs around 11g on average and has a diameter of about 20mm. The inscription on this coin, which is entirely in Arabic, is not particularly special as very similar inscriptions are found on other coins also. One slight difference to note is that the date (730 AH) is written in words rather than in numbers. One interesting fact is that there is a possibility that this coin wasn't one made from the royal mint but rather was a forgery.