My grand father get some property from there parents now he expir

My grand father get some property from there parents now he expired unexpected due to heart attack in 2006.my grand father has two daughters and one son.2 daugthers got married in 1970 and for another is in1980.at the time of marriage he given 3acres of land for each daughter as a dowry as a gift,and my grand father has another 6acres of land,my grand father and my father is lived in onehouse only.my father is having some bad habits like drinking etc... in that 6 acres land my grand father sold 3acres and buy 10acres on his name (grand father) and 5acres on my grand mothers name in village..due to my fathers bad habits my grand father put all the property on my grand fathers name only.now suddenly my grand father was expired with out writing any will...my father is enjoying the property..suddenly my father is also expired after 10years..now all the property is in my handover.now aunties(two daugthers of my grand father) are coming and fighting with me that this property belong to my father(grand father)we want share in this property. at the time of marriages my grand father given equal shares to daughters.dues to bad habits he had not given nothing to my father and nothing is there for me and my mother. I am having all the property documents with me only. my grand mother is witth them only and she support to his daughters only. after my father expired i collect all the documents of my grand father given to his daughters. now can you please suggest what is law in this issue and what should i have to do.can go legally by court.. now there is another problem government is saying that this property is forest land but we having all registered documents and passbook also. please suggest me what should i have to do....