For seeking partition there is no time limit.
your father's sisters are also class I legal heirs to their parents, specifically legal heirs to the deceased property owner who died intestate.
Being class I legal heirs they are also entitled to an equal share in the property left behind by their mother.
There is no legal infirmity in their claim for a share.
If partition is not possible at this stage all the brothers may jointly agree to contribute amount which shall be shared by all their sisters as a compensation to their shares in the properties under their possession now.
If the court is not able to partition, it may bring the entire property to sale and the sale proceeds shall be divided equally and distributed to all the legal heirs.
Avoid unpleasant situation.