Partition suit

Yes, in your case the Hindu Succession Act will prevail. 
Check on following https://goo.gl/TWa7L6

IN case of Father: It is simple case of inheritance (Intestate Succession).

ClassI Legal heirs of Hindu Male i.e; Mother (if alive as on date of death), wife (Your mother; as per your posy she was alive on date of death of father), sons and daughters………… shall share equally.

If mother (of your father) was not alive as on date of death then each ( wife+5children) should get 1/6th share.

Submit Death certificate of your father and mother, mother of your father, legal heir certificate, requisite forms/annexxures to authority under whose jurisdiction property falls and complet the process for Intestate Succession, to record inheritance. Obtain latest mutation records.

Property that devolves by inheritance is of Nature; Self Acquired.

In case of self acquired property of Hindu Woman: the 1st right is of Husband (if alive as on date of death. As per your post he i.e. your father predeceased his wife i.e. your mother), sons, daughters.

So 1/6 share of Mother shall be equally (1/5th) devided amongst her sons and daughters.

You can either offer to buy other’s share or let them enjoy or partition amicably and register the partition deed or partition thru court or register family agreement of fair and equitable terms.