1. Whether sister of my father can claim for her share in proerty sold during 2001 (prior to 20.12.2004) by my father.
If this was your grandmother's own property, then upon her intestate death the property shall devolve equally among all her legal heirs. Therefore your father without identifying his share in the property or proper partition of the same cannot sell a major portion of the property left behind by his mother on his own without allotting the sale consideration to other legal heirs.
The question of a daughter entitled to a share prior to 20.12.2004 in this case shall not be applicable. She is entitled to share from her mother's property as her legal heir as per the Hindu Succession Act originally enacted in 1956 giving equal rights to the daughters in the property left behind by their parents who died intestate.
Therefore your father's sister is entitled to a legitimate share out of her deceased mother's property.
2. Still remaing land of 3.75 dismil is on my grandmother name than who can be present claimant in that left land
All the three legal heirs of your deceased grandmother, i.e., her sons and daughter are entitled to an equal share out the property containing 7.75 dismal, therefore an amicable solution can be arrived by sorting out the issues within themselves to avoid prolonged litigation