Hello divya,

I'm assuming you will 20 years old when you will be eligible for the examination, according to the information provided by you ,the standard wieght for your hieght is 46 KGs, and the acceptance is plus or minus 10% of the standard wieght, so please try to exercise and be fit before the appearance in the examination.

There are different coaching centres for CDS preparation, and it's totally depends on you what you prefer in a coaching institute according to your learning capacity, distance limitations, time management and classroom environment.

1. SSC UNIVERSAL Councelling
2. Doon Defence Academy
3. Anupam defence Academy

These are some top coaching institutes,you can also try some online coaching platforms, they also gather best teachers for you, and provide good notes.

Best of luck,

I hope it helps