Quitting engineering at this peak point ie 3rd year is not a very good idea in my recommendation.still you can apply for CA at this point if you really think you are into this.register and fill the form.explore ICAI website.In fact it would be a bit easier for an engineer to crack CPT(common proficiency test) paper of CA. the difficult part being only ipcc and finals.choose wisely between the two streams.
All the best!