Hi my father is 65 years old. he is not sick but he is complaining for everything if he does not like things/daily work/people. he is talking all the un necessary stuff even though nobody brought up or not interested. is it schizophrenia?

No but he could be in the early stages of dementia. Infection is another cause if rapid onset of symptoms. He should be evaluated by his physician to determine the best course of action.

It would be quite unusual at age 65 to present with schizophrenia, and much more likely is depression or dementia. A visit to a psychiatrist could sort this out and develop a treatment program.