There are big difference between CA and B.Tech. Both are of different type of education. B.Tech is a technical education and the C.A. is a commercial education.

after C.A. you can work as chartered accountant in any company or open your office to do work.

You can do C.A. if you have much interest in accounting or you want to start your own business to use your abilities of both in your own business. As before starting own work we must know all aspects and facts in the business. We can say, we must be all rounder.

CA and b.tech are two different streams, one is north pole and other is south pole. CA is for those people who wants to make their career in accounts and finance division.