You can easily take admission in CA. There is no such issue of having maths as a subject in your 12th.
But yes, after taking admission in CA , you have to study Maths for CPT.
Further many of the mathematic concept will apply in CA course in its second level & third level. You need not to worry, you will slowly & steadly understand all the concepts & methedology. You only need to have strong determination.
Stay happy & bright...