How to pursue CA alongwith CS? Is it possible?

Yes definitely you can do both of the courses simutaneously. But one thing is sure that you need to be hard working. Both of the courses are best in their own terms and require a lot of hard work to get through.

Another thing to consider is, that your articleship will be a big hurdle to manage studies for both the courses alongwith your studies.

Being said that, there are alot of topics which overlap under both the courses and this will give you an advantage in both the streams.

Also, you won't be requiring much of the coachings for CS as you would have already studiied 70-80% of your syllabus in CA and the rest can be easily completed through self study.
Personally, I would suggest you to focus on CA and keep CS on the side track (Like weekends and holidays) but keep preparing your notes for boths and don't lose the track.

Strategy would be maintain consistency (2-3 hrs of self study daily) alongwith constant motivation.