I want join the indian air force ?

If you are studying Physics and Mathematics in 12th, you are eligible to join IAF through the NDA. The exam is conducted twice a year and they invite applications around June and December every year. Check details at the website of UPSC.

If selected, you have three years training in the NDA along with people who would be going to Army & Navy too. After this, you get a BSc or BA degree depending on what you studied there. Then, another one year of training in the IAF and you would be commissioned as an officer in the flying branch of the IAF.

There are two more entries through CDSE and through AFCAT examinations for graduates who have studied Physics and Mathematics upto 12th class. CDSE is conducted twice a year by UPSC. AFCAT is conducted directly by the IAF in the same frequency. Check UPSC website or Career Air Force for further details on this. The total training period is for 18 months before getting commissioned.

Point to note is that you need not have completed the course when you write the examination and could show proof of passing the exam (12th or degree) on a later date before actually joining training.

Check the link below.

http://www.apnaahangout.com/how-to-join-indian-air-force-www-careerairforce-nic-in/