Hey Noor.

To join Indian Army as an Officer, Commerce stream students have two ways-

After 12th (NDA Entry)

After Graduation (CDSE, NCC, JAG Entry etc, whichever applies)

In case of joining Indian Air Force and Indian Navy as Officers, there is no provision available for Commerce students right after 12th. They may join Indian Navy or IAF after Graduation though!

A good example is the AFCAT examination. Commerce stream students may join Indian Air Force as Officers (in Ground Duty Branches) after Graduation, by appearing for AFCAT examination!

This exam can be attempted by candidates who have completed graduation from a recognized University. So, after completing graduation course (3 or 4 years long), Commerce stream students may appear for AFCAT entrance examination and join IAF’s Ground Duty Branches. Similarly, they may appear for relevant exam held by Indian Navy also, after Graduation and join Indian Navy as Officer.

After clearing the written exam, candidate has to crack the SSB (Services Selection Board) Interview, before the candidate gets selected for the training program and become a Commissioned Officer in Army/Navy/Air Force.

Hope this serves your query. Please feel free to respond and ask further questions. 

All the best.