1. Your parents can do whatever they wish with their self acquired property on which you have no right at all,
2. On ancestral property you have equal right alongwith other legal heirs of the said property,
3. However, the meaning of ancestral property as per law has to be made clear first before claiming its share,
4. If your great grand father leaves his property which has not yet been divided, partitioned, willed, settled or gifted till date which is enjoyed by all the co=percener, then it is an ancestral property to the 4th generation i.e. the great grand daughter/son being you,
5. If there is an ancestral property of yours, file a partition suit claiming your share in it.