Women had rights since Indian Succession Act of 1956 on "Self Acquired Property". The amendment in 2005 gives rights to women for ancestral property (i.e property considered a Mitakshara Coparacenary, Dayabhaga, Nambodri, etc systems). The rights to the women were given retrospective and was deeded to be acquired by birth and on or after the date the Indian Succession Act was passed (i.e in 1956 with amendment applied). If the ancestral property was partitioned before 2005 or Dec 2004, the woman cannot ask for partition.
Few states (AP, Madras, Kerala, etc) had passed a similar amendment earlier. If the property is in any of these states you may have rights from an earlier time. You will need to consult a good lawyer who can look at your specific case and advise appropriately.