You probably have a 6 kreuzer, 1848 to 1849, from Austria, when Franz Joseph I was king. This coin is made of silver, but the fineness is low (43.8% silver), so there is not much value due to silver content.
When a coin is struck after the year shown on the coin, it is called a re-strike. For the 6 kreuzer, coins dated 1849 were struck in 1848, but also between 1850 and 1852, and restruck again during 1859 to 1870. Re-strikes carry the same value as normal strikes.
The coins carry three mint marks, A, B, or C. Values depend strongly on mint mark, but the date (1848 or 1849) does not affect value very much. Below are approximate catalog values
COINS DATED 1848A OR 1849A:
worn: $3 US dollars approximate catalog value
average circulated: $5
well preserved: $15
fully uncirculated: $35
coins dated 1848 are worth a little more than these values
coins dated 1849 are worth a little less than these values
COINS DATED 1848B OR 1849B:
worn: $30 US dollars approximate catalog value
average circulated: $60
well preserved: $250
fully uncirculated: $450
COINS DATED 1848C OR 1849C:
worn: $6 US dollars approximate catalog value
average circulated: $10
well preserved: $40
fully uncirculated: $80
These are catalog values and they must be adjusted to get actual buy and sell values. Please read our Important Terminology page to understand how to interpret catalog values.