Hello Rengaraj,
Yes, you can study CA, even after completing the CMA course.
The advantage is that you would have an upper chance of getting selected at interviews compared to your peers.
And for the further details, if you have any query you can even visit our website, where there is a detailed description which would be quite helpful for you https://www.careers360.com/
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile