Hello Ritika,

As you maybe already know that females can only apply for CDS OTA (Officers Training Academy), normal CDS exam is for men only. In CDS OTA, Mathematics is not asked.

There are only two sections : 1. General Awareness and  2. English.

Syllabus for General Awareness section:

• Current affairs

• Art and culture

• Economy

• History

• Geography

• Books and authors

• Chemistry

• Physics

• Biology

So, please choose the subject for your bachelors in which you're most interested, physics, chemistry or biology. You can even go for BA hons if you want to.

Whatever subject you may choose, remember that exam is just the easiest step to finally get selected to armed forces, you should start to prepare for SSB side by side.

Hope this Helps!

All the best!