Can I start preparing for C.A at age of 29

Of course you can Sir. There is no age limit for persuing CA. Only the focus matters. If you are really interested in pursuing CA, start it as soon as possible. All the best for your CA Carrier.

ofcourse you can if you have will power for that there is no any limitation

Yes you can definitely start preparing for CA at the age of 29. CA is a course where there is no age limit, so it doesn't matter when you start for it. If you really have an interest becoming CA, then you can definitely start right now for it. But if you are already doing a job then don't leave it because there is a risk factor in pursuing CA. Keep doing your studies along with the job. But if you are in business, then you can easily start your studies along with the business.