Each currency coin minted in India (for that matter anywhere in the world) has a special mint mark on it to identify the Mint.
The Bombay (Mumbai) Mint
Bombay (Mumbai) Mint has a small dot or a diamond under the date of the coin (year of issue). The Proof coins from this mint have a mint mark ‘B’ or ‘M’.
The Calcutta Mint
Calcutta mint has no mark under the date of the coin (year of issue). Many people confuse “c” found under some coins to be from calcutta mint. However, that symbol belongs to the Ottawa mint in Canada.
The Noida Mint
Noida mint has a dot under the year of issue (coin date).
Many of the India coins have been minted in foreign mints over the years. Some of the mint marks of these foreign mints are given below.
Royal Canada Mint
The Royal mint at Ottawa, Canada has a small letter “c” as the mint mark which is placed beneath the year of the issue.
The Seoul Mint
Seoul mint mark is a five point star. The mark is placed exactly on the first or the last digit of the year of issue (date of coin).
The Royal Mint London
The Royal mint at Birmingham has a small dot which is placed exactly on the first digit of the year of issue.
The Moscow Mint
The Moscow mint has a mark MMD under an oval which is placed under the year of the issue of the coin.
Heaton Press Mint UK
The Heaton Press mint UK has a mark “H” under the last digit of the date. The symbol is decorated.
Mexico City Mint
The Mexico City mint has a mark “M beneath o” under the date of the coin (year of the issue)
The other foreign mints where Indian republic coins were minted include Kremnca Mint, Pretoria Mint (South Africa) and Dominican Republic mint.
Images courtesy: Jina datha & Bha rat Coins