Can a woman sell land without her son's consent?

My Grandfather buy land from others long back ago. Few years ago, my Grandfather passed away due to health Issues. Where in my grandmother have taken amount from outside for medical bills and his son didn't ready to repay those payments. So, my grandmother Decided to sell the land, where he is not willing / not allowing to sell the land or either repayment of Amount. Family tree: My grandmother has 4 daughters and 1 son: Every one married and son has no children - daughters are supportive to mother. what would be better course of Action where my grandmother willing to sell the land without his son Consent?