I understand your concern. Your grandfather seems to be suffering from dementia symptoms. However more clarity is needed regarding his problems to decide on the severity and to rule out any other acute confusional state causing these symptoms. Has he sustained any head injury? Is he diabetic or hypertensive? Information is needed regarding these as well. He would require a detailed evaluation with a neuropsychiatrist for the same. It is manageable with appropriate treatment including medications and counselling. My clinic is at OMR chennai. I would also be more than happy to help you with that if you are looking for further online assistance. You can directly consult with me through Practo as needed. Online chat consultation is also available.