See if you are a commerce student then you need to have Mathematics in your 11th and 12th because the top colleges always require mathematics as an eligibility criteria for BCOM.

Now as per your interest your should take the subject. Many people take PhE because its easier as a subject and not a much of studying is required. So you get less pressure. But if you take Computer Application then the skills you will learn can help you if you want to go for BCOM Computer Application or BCA degrees. As you know nowadays, having moderately good computer knowledge is very important for jobs. So if you want to learn the skills then I would say Computer Application will be a better choice.

To know more about Commerce you may visit the link below:

https://www.careers360.com/courses/commerce-course

I hope this answer helps. All the very best for your future endeavors!