Need advice

In my mid 9 class I have been selected for admission in Rashtriya Military School Chail after qualifying written exam and interview in 3rd merit list Now the doubt I have is that I don't want to join defence on which RMS focuses I want to join civil services so should I join RMS currently I am studying in Lucknow Public School a block South City. The fees of RMS is comparatively low than of my school.

So I request seniors any advice what to do I very confused