grabd mothers veelunama

Hi knowledgeable people, I have a question regarding my grand mothers veelunama (Telugu) where she wrote that income on her assests can be enjoyed me ,but selling rights only to my son. 1) my wife have fertility issues since 5 yrs. How does law say if I don't get kids? 2) what if I give birth to a girl child only? Does girl child will have rights? 3) if we adopt a boy/girl will they get rights? 4) even though she wrote a veelunama giving selling rights to her grand grand son, as a grand son won't I have rights to sell land?