Ancestoral property-letter of administration

Hi , This is with reference to agricultural-ancestoral land that my father had a part, along with his only brother. my dad had only 1 kid that's me. He died without any will. As per my understanding , his part of ownership(1/2 land) would be divided into below parts a) One part to his wife ( my mom) b) Second part to me. Since we lived in mumbai , we( mom and me) raised a request for letter of administration for the said property. While raising the request i gave the "no-objection" , so the honorable highcourt granted the letter of administration in the name of my mom only . Now while trying to sell the land , the buyer says that there is only mom's name written in letter of administration . There is no mention of "my no objection" in the letter of administration issued by high court and i can raise an dispute down the line. Please suggest on the same so that the property can be sold thanks & regards mahesh