Hello,

Usually people after 12th give a exam called NDA which is held twice a year . If you have cleared the exam you will be called for interview( SSB interview) . It is of 5 day of interview which has group discussion , personal interview , some physical tasks. If you have cleared that also then you will be selected and your training will start after the training you can join IAF.

If you are a NCC candidate then if your training is completed and got 'C' certificate from the NCC Air wings then also you can join IAF.

I hope this helps.