Dear Himanshi, there are following options for you to join defense after your BA defence and strategic studies:

1. UPSC Entry- Here you can enter by Short Service Commision Women (Non-Technical) Entry Scheme. You have to clear CDS, followed by SSB. 12 women are selected every six months for the beginning of training based on the merit list. The training is of 49 weeks held at OTA Chennai beginning every April and October.
2. Non-UPSC Entry- In Non-UPSC entries, there are two entries: NCC Special Entry and JAG Entry, both of which are Short Service Commission and for Women. NCC ‘C’ certificate is compulsory. There is no need to attend any CEE for this entry except for a minimum of 50% in graduation with a valid NCC ‘C’ certificate with minimum ‘B’ grade Shortlisted candidates will be called for SSB. 4  women are selected from the merit list to undergo training at OTA Chennai. The training is of 49 weeks held at OTA Chennai beginning every April and October.
3. Rest are Tech and Law streams, which does not match up with your educational requirement.

I hope this helps you!