You have a B.Tech, no GATE and a career in teaching is your choice. No time to spare
1.In this scenario, as a fresher your scope is limited. The traditional teaching jobs would need a M.Tech, good experience and GATE (can become instructors with good pay).
2.You have to think outside the box and take a few chances. Try to apply for jobs that are offered by innovative or new firms that need teachers for their programs/education center. For instance, like these teaching jobs (https://www.naukri.com/btech-teacher-jobs) (https://www.freshersworld.com/jobs/category/teaching-job-vacancies-hyderabad). A few privative engineering institutions would offer a Lecturer job on contract or temporary basis, you can apply for this.
3.There are many jobs for freshers, short-term that does not have a title of lecturer. They will have trainer, tutor, online support coordinator or even counselor. You can try these as a stop-gap arrangement.
4.Once you are into this then quickly start doing your M.Tech. IGNOU, has M.Tech in 10 sub-specialties (http://ignou.ac.in/upload/Master%20Degree%20FC_2012%20New.htm). Enroute to your M.Tech you can decide your next course of action, taking GATE or other teaching relation exams.
5.One such exam would be the National eligibility test (NET), this is like an alternative to GATE, gives you chances of scholarships, employment at UGC pay scales and a good shot at getting settled in a long-term career/job.
6.From step three, if you want to pursue a job as a teacher in a government or a good private school, then you can choose a distance mode B.Tech from IGNOU or a UGC recognised university and then you can take up the national TGT exams(trained graduate teacher).