Will of succession

Hello, My father died inte se, without a will in Varanasi . I am his biological daughter, and he has adopted my mother's daughter, my half sister. Not clear if a registry was done possibly. I am having many problems in inheritance issues with my sister.she resides in Spain and is a Spanish citizen. I am a NRI in Thailand. My questions are: Does a non biological adopted child has the same rights to inheritance of property? A will of succession I believe is being drawn up, without my participation, ( I signed papers under duress in Hindi mid September, I believe for the papers to be presented). The plans were that they would be ready by December. but I, the biological daughter have no access to the advocate, whose details I did not take down in Varanasi. On requesting for the details, a silence as to his contact information. I have asked for the papers to be sent to me ahead if time, with an attested English copy, but again no participation to the basic requests. I am afraid that my cousin who has many contacts might get the will of succession approved in my half sister's name, and then I believe I would have no access to what is rightfully mine. My father has two properties. One in Gurgaon and another in Varanasi. Deeds of conveyance are required for both to process papers?The house is in the name of my father as a primary member, both properties. My mother survives, but is rather old and bedridden. I believe she can easily be manipulated by my sister and cousin brother acting on her behalf. P Should I be aiming for an inte se registration along with my mother, or a will of succession? I have been speaking to a advocate who is in charge of the Girgaon society where my father owns a home. His suggestion is to move forward in blocking any papers that may have been presented in Varanasi court, and to begin presenting a will of succession under Gurgaon jurisdiction as property is located in Gurgaon. What should I do?