There is no such particular age at which you are too old to start acting. People who say that you can become successful actors only if you start to act at a young age is completely absurd. There are examples of many people in the film industry who have started to act late in their lives but have grown extremely successful.
There are many such actors also who started acting at a very young age but have not grown to be successful. The age plays no role to start acting. Your passion and dedication is the thing that matters and can make you a very successful actor.
What are the features that you need to become a successful actor?
First of all, you should realize that age, looks, caste, creed, etc. cannot prevent you from acting. The important feature that you need is your acting skills and your dedication towards acting.
It is never too old to become an actor. Many people realize that their passion lies in acting. You will always have time to become an actor and should have the courage and patience to grab the perfect opportunity. While you start to act, you might get small advertisements roles or some playback dancing roles. You should never be sad to take such roles; in fact, you should opt for these roles happily and work hard so that people recognize you and take you in bigger projects.
You should have the dedication to the role you are given. Hard work is a key attribute required by an individual to remain in the film industry. You should never rest on your laurels and work each day more always to grow and enrich yourself.
If you yet think that is it too late to start acting, then you should change your thinking. A person older is having more experience than a person younger in age. He may give more realistic acting in a role as he has more experience and might have also gone through it in real life. If you are changing your field at such an old age, that means you are very affectionate about acting and will give more than his/her best in acting.
Thus it is never too old to start acting. Many people have to choose to act at a late age. You should consider them as your mentors and start working hard for it.