Ancestral property partition

Share of your sister is intact, which cannot be transferred by your father or anyone else.without her written consent.

The posting is short of material facts. How is that the property is ancestral? Other than your father who elase are the holders or the parcenors?

Dear Arun the half that your father has already made a release deed under your name, is infact yours, given that it was before 2005. 

However, the other half which was under your father's name can be claimed by your sister

Even if the amendment in Section 6 of the Hindu Succession Act, 1956 was promulgated and effective from 09th September 2005 yet it is applicable retrospectively in terms of

SUPREME COURT OF INDIA in Civil Appeal No. 8538 of 2011 (Arising out of SLP (Civil) No. 9586 of 2010)
Decided On: 12.10.2011 in case titled Ganduri Koteshwaramma and Anr. Vs. Chakiri Yanadi and Anr.
Hon'ble Judges/Coram:R.M. Lodha and J.S. Khehar, JJ.Citation: (2011) 9 SCC 788 19 has held 

Accordingly, we hold that the rights under the amendment are applicable to living daughters of living coparceners as on 9-9-2005 irrespective of when such daughters are born.

Disposition or alienation including partitions which may have taken place before 20-12-2004 as per law applicable prior tothe said date will remain unaffected. Any transaction of partition effected thereafter will be governed by the Explanation.”
 

23) The law relating to a joint Hindu family governed by the Mitakshara law has undergone unprecedented changes. The said changes havebeen brought forward to address the growing need to merit equaltreatment to the nearest female relatives, namely daughters of acoparcener. The section stipulates that a daughter would be acoparcener from her birth, and would have the same rights and liabilitiesas that of a son. The daughter would hold property to which she isentitled as a coparcenary property, which would be construed asproperty being capable of being disposed of by her either by a will or anyother testamentary disposition. These changes have been sought to bemade on the touchstone of equality, thus seeking to remove theperceived disability and prejudice to which a daughter was subjected.
 

The fundamental changes brought forward about in the Hindu Succession Act, 1956 by amending it in 2005, are perhaps a realization of the immortal words of Roscoe Pound as appearing in his celebrated treaties, The Ideal Element in Law, that “the law must be stable and yetit cannot stand still. Hence all thinking about law has struggled toreconcile the conflicting demands of the need of stability and the need ofchange.”

24) Section 6, as amended, stipulates that on and from the commencement of the amended Act, 2005, the daughter of a coparcener shall by birth become a coparcener in her own right in thesame manner as the son. It is apparent that the status conferred uponsons under the old section and the old Hindu Law was to treat them ascoparceners since birth. The amended provision now statutorilyrecognizes the rights of coparceners of daughters as well since birth.
 

The facts posted suggest the property not to be ancestral. Had your father executed release deed or gift deed or is it a settlement deed?