Property Claim

Hi! I'm Yash, 24. My mom passed away when I was 2 years old. Recently my mothers' parents i.e. my grandparents expired. My grandparents have 4 sisters (out of which my mom was one of them) and only elder son. When I was growing up,u grandfather used to say that he has a lot of saving, insurance and shares under my name. However all of these facts have been rubbished by my relatives now. I want to know if I have a claim on the property which belonged to my grandparents? Do I have any rights on it? Do my rights end with my mom passing away? Any professional advice granted, would be a great help. Thanks.