Gift of house through Will

Namasthe Sir, My deceased mother-in-law's eldest sister (single person, no children) gifted her own house (her own self asset) to my wife and me through will during 2006 & after a month she passed away due to cancer. In 2012, my wife and me registered this property in BDA (Bangalore Development Authority) and built a building. We are paying regular taxes and looking after the building maintenance. Now this year I wanted to sell this property and buy two more houses from this money (approx 2 cr). Some prospective buyer took the xerox copies of the will, mother deed, registration details, khatha extract, plan etc; but he is doubting that "My wife and I cannot sell this house" as this is gifted to both of us through a will. I tried to educate the buyer, but asked him to take legal opinion. Now my question is are we (my wife & me) not the owners of this property? If Yes, why this buyer is coming with such doubts? Who has the rights to sell this property? Thanks a lot in advance for your advice Sir. Namasthe. Best Regards - Gopi