Dear aspirant hope you are doing well..

To get a career in India army after completing B. Sc nursing.. You have to crack CDS Exam..

Entry with Combined Defence Service (CDS) Examination

The most frequently and easiest ways to join the Defence Forces after the bachelor's degree is to take Combined Defence Service Examination. Your age has to be between 19-24 years. Your graduation should be from UGC recognized university or institution.

For more details about CDS entrance exam, eligibility criteria, syllabus, exam pattern, pervious years questions paper and more. You can read the given article. Link is given below.

https://competition.careers360.com/exams/cds/amp

Hope it's helpful

Thank you