1. You can very well file a suit for partition seeking your father's legitimate share in the property on the basis of intestate succession of the properties that were lying on your grandmother's name.
For the filing the parition suit, there is no limitation.
2. Since your grandfather had transferred his property to his wife by a registered gift deed, she becomes the absolute owner of the entire property that was transferred to her name.
Now, upon the intestate death of your grandmother in the year 1992, the properties lying on her name shall devolve equally on all her legal heirs, which includes your father also.
Since your father is reported to have died intestate, his share out of his mother's proeprty shall devolve upon his own legal heirs, hence you can very well file a suit for partition and seek separate possession of your legitimate share in that property.
3. In this situation you can ignore the event namely your father's sale deed to his sister in law etc.