Can cancer recur within six months of operation?

Hello doctor,

My brother-in-law underwent an operation on the right side of the CA tongue, followed by radiation and chemotherapy six months ago. For the last two weeks, he has had pain on the left side of the tongue, and we consulted the doctor again. The doctor said there was no possibility of further operation and radiation therapy. He suggested that he needs to go for chemotherapy only. Though we opted to go for chemotherapy, his body could not support it. He became very weak as he had already undergone surgery, radiation, and chemotherapy. This also has more side effects, and he will be unable to resist. Also, the doctor said that there is no scope for curing. Hence, he advised me to go for medicine, which equals chemotherapy. I kindly request you to give the best possible solutions to save his life. Is there a possibility of cancer recurrence on the left side within this short period? What is the stage of cancer before and after the operation? I have attached his current medication. Is it fine to continue?