Since you are an M. Tech degree holder, you will do well to try for a job in a self financing college. For your information, you can easily find a good job in cities like Hyderabad, Chennai, Coimbatore, Cochin and so on, where are there a huge number of Engineering colleges, where the teachers tend to switch jobs so often.
For the time being, you can join the school job, if you can't find one in the cities. However, if you go over to a school, you need to do the B.Ed course, without which the teaching will not add any value. You cannot get promotion or higher salary without this degree, for which so many Universities offer you the degree through correspondence.
A better alternative may be to go to a big city like Hyderabad, and submit your resume in any college. There are always vacancies and you are willing to accept duties of a hostel warden, you will be given food and accommodation free. So, consider this kind of an environment and do it to get your part-time doctorate degree, from the JNTU, Hyderabad. You cannot aspire for any good settled job, without the doctorate degree.
So, plunge into it and get the doctorate degree at any cost. All the best.