1875, Victoria Queen, Copper 1/2 Anna, Calcutta Mint, Reverse die rotated to 10'o clock, (PR# 583), About Very Fine and above, key date in half anna and this coin has the die rotation variety, Extremely Rare.
Similar coin of Proof Condition was sold for around Rs. 9,50,000 by Baldwins, London in May 2013 and of Very Fine Condition was sold for around Rs. 2,20,000 by Baldwins, London in September 2013.