After reading your query, I got engaged in calculations. As per the details you have provided, I guess that you have a gap of around 8-10 years now. After this much gap, a technical field will not be suitable for you. You may go for short term refreshment courses in the field related to M Tech, but again your gap and your age will be drawback points for you in that field.
There are many private and government institutes offering this course through correspondence but being technical in nature, it is not advisable to pursue the same through correspondence that too when you are pursuing this to have good job options.
Regarding B.Ed, if you have core interest in teaching, then only go for it because teaching is a challenging job. But if you really are, then pursuing B.Ed. can be a good option for you. Yes, you can enroll for correspondence also but you have to appear or manage your demo classes as per the schedule the Institute assigns you.
Apart from teaching after investing your money and precious 2 years for B.Ed, I would suggest you join coaching classes. There are a lot of them in most of the cities. There you can teach the subjects of your choice and then the working hours are less and that too flexible. You can manage as per your availability.
Another option is to try in private banks. Nowadays, when banks are getting digital, technical staff is the requirement of all banks and you may try for that.
Living & Learning- simultaneous processes!