You need to be qualified enough to be doing that course , maximum qualification for a flight attendant is to be good in communication skills specially in foreign languages.I suggest you must be a graduate tha will help you to grow in your career.

Dear Tripathi
The minimum qualification required is Class 12. It pays to be a graduate in any field or in hotel management. Knowledge of a foreign language is an added advantage. Some air hostess training academies help you train for the job


Institutes for this career

Frankfinn Institute Of Air Hostess Training

Avalon Academy

Frankfinn Institute Of Air Hostess Training, Kolkata
If you want more details, go through their official website.  So that all your doubt get solved.
All the best.

but sir defence is not my iterested field ,, so is there no exams after th for flight attebdebt

Best is apply for NDA. otherwise complete your graduation first, then all you understand what should you have to do..