Indian coins are mainly produced in 4 cities:
- Delhi 
 
- Mumbai
 
- Hyderabad
 
- Kolkata 
 
The production in city puts an identification mark under the year of issue.
Coins produced in:
- Delhi - have a dot 
 
- Mumbai - have a diamond
 
- Hyderabad - have a star 
 
- Kolkata - Nothing beneath the year
 
Isn’t it amazing? 
Most of us don’t know this