You do not have any rights in your step–father’s property as his children and your mother, being class 1 legal heirs, will have right over his estate.
In such a situation, you are well within your rights to claim your 1/3rd share in the property. An appropriate suit can be filed in a court of law.
To answer your query, the disqualified legal heir can challenge the Will as no reason has been given to disqualify him by the executant of the Will. Will can also be challenged on the ground that it was made due to undue influence, duress, or lack of mental capacity.
Please note that the partition suit varies from case to case. There is no prescribed timeline for the conclusion of the suit. However, on an average, it takes about 2 – 3 years to get the property partitioned.
In such a situation, an appropriate suit seeking partition and declaration can be filed in the court of law claiming your share in the property.
Since the property possessed by him is in the capacity of a caretaker; as a result, he cannot claim his title over the same. An appropriate suit can be filed against him so that he gives the peaceful vacant possession to your father. Thereafter, the sale can be executed.
Firstly, the legal heirs of the deceased are required to file an application to concerned department along with the requisite documents like the death certificate of the deceased, identity proofs of the legal heirs etc. Next, if no objection is made by the authority, then the certificate is granted.
In such a situation, the property owned by your father shall devolve upon you, your siblings and your mother in equal shares. For this, an appropriate suit can be filed in a court of law if all the legal heirs do not agree for an amicable settlement. If all the legal heirs agree, then the property can be transferred in their names by approaching the concerned authority.
A complaint has to be filed within two years from the date on which the cause of action/deficiency in service arises. However, a complaint may also be filed after the period of two years, if the complainant satisfies the Forum that he/she has sufficient reasons for not filing the complaint within such period.