DEAR MONICA,
.first of all i am sorry to inform you that you are not eligible to join defence services now
.because at this stage only a single way is there which is NDA(national defence acdemy)exam conducted by upsc twice a year
.but it is only for unmarried males not for females
.dont worrt about that you can complete your graduation and the try for it
.after graduation in non-technical field from a recognized university you can give the exam of
SHORT SERVICE COMMISSION FOR NON TECHNICAL WOMEN
conducted by upsc under COMBINED DEFENCE SERVICES
.age 19-25 year
SHORT SERVICE COMMISSION FOR TECHNICAL WOMEN
age 19-25 years
.engineering degree
.ALL THE NOTIFICATIONS ARE AVAILABLE ON THE SITE
http://www.upsc.gov.in
...........................................best of luck for your bright future..........