Coins minted from 1862 through 1873 all have the date 1862.

The 1/2 Anna coin has two Reverse designs, which can most easily be identified by examining the "1" in the date.

Reverse I - The "1" in the date has a slanted top. The word "ANNA" has narrow spacing. Note the position of the A's in "ANNA" almost immediately below the "H" and "F" of HALF.
Reverse II - The "1" in the date has a flat top. The word "ANNA" has wide spacing. Note the word "ANNA" is much wider than the word "HALF" above it.

Wide and Narrow "7" - The 1877 C/II Calcutta issue has short, wide 7's in the date. The 1877 B/II Bombay issue has tall, narrow 7's in the date.