Hii,

If you want to clear this exam then you should focus more on self-study. Coaching centers have nothing to do with your selection. What you really need to do is to make a plan and study according to it. Solving previous years question would be a great help to you. But as per your question here is a list of some of the good coaching centers which can help you:

a) Doon Defence Academy

b) Major Khalsi Classes, Allahabad

c) Trishul Defence Academy, Allahabad

d) Cavalier India, Lucknow and Delhi

e) Step2 Defence, Lucknow

Hope this helps.

All the best!!