Hello, after 12th there is option to join the Airforce through the technical entry scheme. The candidate need to have 70 percent aggregate in PCM from any recognized board and the candidates will be selected through interview process. Further you will assigned to study the engineering course followed by your appointment as the lieutenant. The application is invited twice a year in the months of  January and July. For more details kindly visit this link to know about TES https://competition.careers360.com/articles/Indian-army-tes#Indian-Army-TES-Eligibility-Criteria-2020

Best wishes.