mace was an important part of early days in ancient Indian warfare but was slowly going out of use by the time of Mauryas with development of advanced metallurgy. by the time of the Imperial Guptas, maces or gadas were all but absent as a battlefield weapon.
it is still used however as an exercise and body-building tool. there are two general types, a solid wooden one with handle (size can vary from 2 feet to about 4 feet) and the lollipop one.
http://www.youtube.com/watch?v=TUgQ0q9sLmE&
http://www.youtube.com/watch?v=GP_ow_7gbB8
what CC and Prometheus has depicted is the exercise version in the 2nd vid.
the version on the far left from a TV version of Mahabharat is an accurate depiction of the Gada(war-mace) and matches with the description given in the Mahabharat. (be warned though, the rest of the weapons, costume, hairstyle etc are complete nonsense )
another view of the same Gada on the left, the one on the right is completely wrong though.