Air Force Officer

You are eligible for airman in IAF.

You are eligible to join ground duty administration and logistics branch as a commissioned officer. You may apply for AFCAT on completion of BBA.

Dear Parminder,
Every year the Air Force conducts SSB. You can take part in it. Moreover, There is an exam conducted for it every year named AFCAT. You can apply for this exam to join Air Force.

The eligibility criteria to join admin branch of Indian Air Force (IAF) is as follows" Graduation degree (minimum three years degree course) in any discipline from a recognised university with a minimum 60% marks or equivalent". You will be considered for Air Traffic Controller and Fighter controller roles once you join Admin branch. By the way, you are also eligible for accounts branch of IAF.

You are eligible to join as an airman in technical streams of Indian Air Force subjected to meeting other criterion. You are not eligible for Commissioned Officer job in IAF based on your current educational qualifications.

No, you can't do that. But, you can join Indian army through open selection, CDS or NDA.

You cannot join Indian Air Force as an officer after 12th without appearing for NDA exam. You can join Indian Navy by joining the prestigious Indian Naval Academy, Ezhimala, Kerala for a 4-year degree course under the 10+2 (B.Tech) Cadet Entry Scheme. The selection is based on JEE Mains score.
You can join Indian Air Force and Indian Navy as an airman or sailor respectively after clearing 12th. You may refer to IAF and IN websites for details on joining these org as non-commissioned officer (Airman and Sailor).

You are eligible to join non-commissioned officer rank jobs in different trades after 12th by appearing for selection examinations conducted by Airmen Selection Centres of Indian Air Force. IAF hires commission officers through NDA exam conducted by UPSC with PCM subjects in class 12th board.

There are multiple career options available to become a commissioned officer in IAF.
You can refer to the below mentioned link for all the available options to join IAF as an officer:
http://careerairforce.nic.in/.
What is your educational qualifications?