1. An unmarried daughter who has attained the age of majority cannot claim maintenance under common criminal code unless she is incapacitated by reason of any physical or mental abnormality or injury". However, she can claim maintenance from her father under the Hindu Adoption and Maintenance Act, 1956, from the property of her father in two cases: (a) When there is joint family property. (b) When the property is his self acquisition.
2. A daughter remains a member of the joint family to which she is born until the event of her marriage. As a corollary thereto, she is entitled to claim maintenance from the share of her father in the joint family property. This is applicable irrespective of the fact whether she has attained majority or not.
3. Maintenance for a daughter includes provisioning for her marriage.
4. If you have ancestral land then you are free to file a suit for partition to cull out your share therein. However, the ancestral character of land has to be proved.
5. Your step mother is now the legally wedded wife of your father, so she will succeed as one of the legal heirs to your father's share in the ancestral property.